A pupil uses an abacus to calculate during a mathematics lesson, amid the spread of the coronavirus disease (COVID-19) at the Thika school for the blind in Thika town of Kiambu county in Kenya October 29, 2020. Picture taken October 29, 2020. REUTERS/Monicah Mwangi

A pupil uses an abacus to calculate during a mathematics lesson, as he respects social distancing amid the spread of the coronavirus disease (COVID-19) at the Thika school for the blind in Thika town of Kiambu county in Kenya October 29, 2020. Picture taken October 29, 2020. REUTERS/Monicah Mwangi

Julie Goldman, Steve James and Mark Mitten, nominees for "Abacus: Small Enough to Jail", pose at the reception for the 2017 Oscar-nominated films in the Documentary Short Subject and Documentary Feature at the Academy of Motion Picture Arts and Sciences in Beverly Hills, California, U.S., February 28, 2018. REUTERS/Mario Anzuoni

Julie Goldman, Steve James and Mark Mitten, nominees for "Abacus: Small Enough to Jail", pose at the reception for the 2017 Oscar-nominated films in the Documentary Short Subject and Documentary Feature at the Academy of Motion Picture Arts and Sciences in Beverly Hills, California, U.S., February 28, 2018. REUTERS/Mario Anzuoni

A Lemur eats a carrot infont of a giant abacus during the Annual Stocktake at ZSL London Zoo in London, Britain February 7, 2018. REUTERS/Tom Jacobs

A meerkat stands on a rock during the annual stocktake at London Zoo in London, Britain January 3, 2017. REUTERS/Stefan Wermuth

A combination picture shows Natsuki Ariga, 9, posing for a photograph at a library (top) and his drawing of what he wants to get for Christmas from Santa, in Tokyo, Japan December 1, 2016. Natsuki wants to get comic books on Japanese and world history. "Santa gives me a present every year for working hard. That's why I practice Electone (Yamaha's electronic organ), abacus and track and field very hard, " he said. Reuters photographers around the world asked children to draw what they wanted to receive from Santa for Christmas. REUTERS/Toru Hanai SEARCH "CHRISTMAS WISHES" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

A black-capped squirrel monkey sits on an abacus during the stock take at London Zoo in London, January 5, 2015. The animal count, a requirement of London Zoo's license, included additions to the international conservation breeding programme such as the three tiger cubs and Philippine crocodiles. REUTERS/Toby Melville (BRITAIN - Tags: ANIMALS)

A woman gets a haircut in front of installations in the shape of a yuan coin and an abacus in Guangzhou, Guangdong province, August 22, 2014. REUTERS/Alex Lee (CHINA - Tags: SOCIETY)

Alan Roseman, former chief executive officer of ACA Capital Holdings Inc. arrives at the trial of former Goldman Sachs bond trader Fabrice Tourre at the Manhattan Federal Court in New York, July 23, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Eric Thayer (UNITED STATES - Tags: BUSINESS CRIME LAW)

Alan Roseman, former chief executive officer of ACA Capital Holdings Inc. arrives at the trial of former Goldman Sachs bond trader Fabrice Tourre at the Manhattan Federal Court in New York, July 23, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Eric Thayer (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre (L) arrives with his attorney Sean Coffey (R) at the Manhattan Federal Court in New York July 23, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Eric Thayer (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre (L) arrives with his attorney Sean Coffey (R) at the Manhattan Federal Court in New York July 23, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Eric Thayer (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre (L) arrives with his attorney Sean Coffey (R) at the Manhattan Federal Court in New York, July 22, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Mike Segar (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 22, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Mike Segar (UNITED STATES - Tags: BUSINESS CRIME LAW HEADSHOT)

Former Goldman Sachs bond trader Fabrice Tourre (L) arrives with his attorney Sean Coffey (R) at the Manhattan Federal Court in New York, July 22, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Mike Segar (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre (C) arrives with members of his legal team at the Manhattan Federal Court in New York, July 19, 2013. The U.S. Securities and Exchange Commission (SEC) accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Eduardo Munoz (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre arrives with members of his legal team at the Manhattan Federal Court in New York, July 19, 2013. The U.S. Securities and Exchange Commission (SEC) accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Eduardo Munoz (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre arrives with members of his legal team at the Manhattan Federal Court in New York, July 19, 2013. The U.S. Securities and Exchange Commission (SEC) accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Eduardo Munoz (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre (C, rear) arrives with members of his legal team at the Manhattan Federal Court in New York, July 19, 2013. The U.S. Securities and Exchange Commission (SEC) accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Eduardo Munoz (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre (L) arrives with members of his legal team at the Manhattan Federal Court in New York, July 18, 2013. The U.S. Securities and Exchange Commission (SEC) accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Mike Segar (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre (L) arrives with members of his legal team at the Manhattan Federal Court in New York, July 18, 2013. The U.S. Securities and Exchange Commission (SEC) accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Mike Segar (UNITED STATES - Tags: BUSINESS CRIME LAW)

Former Goldman Sachs bond trader Fabrice Tourre (L) arrives with members of his legal team at the Manhattan Federal Court in New York, July 18, 2013. The U.S. Securities and Exchange Commission (SEC) accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Mike Segar (UNITED STATES - Tags: BUSINESS CRIME LAW TPX IMAGES OF THE DAY)

Former Goldman Sachs bond trader Fabrice Tourre (R) exits the Manhattan Federal Court in New York, July 17, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre (R) exits the Manhattan Federal Court in New York, July 17, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Paulson & Co. executive Paolo Pellegrini and his wife Henrietta leave the Manhattan Federal Court in New York, July 17, 2013. Pellegrini is a witness in the SEC trial against Former Goldman Sachs bond trader Fabrice Tourre who is accused of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Paulson & Co. executive Paolo Pellegrini and his wife Henrietta leave the Manhattan Federal Court in New York, July 17, 2013. Pellegrini is a witness in the SEC trial against Former Goldman Sachs bond trader Fabrice Tourre who is accused of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Paulson & Co. executive Paolo Pellegrini leaves the Manhattan Federal Court in New York, July 17, 2013. Pellegrini is a witness in the SEC trial against Former Goldman Sachs bond trader Fabrice Tourre who is accused of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Paulson & Co. executive Paolo Pellegrini leaves the Manhattan Federal Court in New York, July 17, 2013. Pellegrini is a witness in the SEC trial against Former Goldman Sachs bond trader Fabrice Tourre who is accused of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 17, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 17, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 17, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Paulson and Co. employee Paolo Pellegrini exits the Manhattan Federal Court in New York, July 16, 2013. Pellegrini is a witness in the SEC trial against former Goldman Sachs bond trader Fabrice Tourre, who is accused of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Paulson and Co. employee Paolo Pellegrini exits the Manhattan Federal Court in New York, July 16, 2013. Pellegrini is a witness in the SEC trial against former Goldman Sachs bond trader Fabrice Tourre, who is accused of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Paulson and Co. employee Paolo Pellegrini exits the Manhattan Federal Court in New York, July 16, 2013. Pellegrini is a witness in the SEC trial against former Goldman Sachs bond trader Fabrice Tourre, who is accused of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 16, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre (C) arrives at the Manhattan Federal Court in New York, July 16, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 16, 2013. The SEC accuses Tourre of misleading investors in a mortgage investment called Abacus 2007-AC1 by not telling them that a hedge fund was involved in selecting the underlying assets and betting against it. REUTERS/Brendan McDermid (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 15, 2013. Jury selection will begin today in the civil fraud case against Tourre, 34, who the SEC says misled investors in an ill-fated mortgage securities investment called Abacus 2007-AC1. REUTERS/Lucas Jackson (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 15, 2013. Jury selection will begin today in the civil fraud case against Tourre, 34, who the SEC says misled investors in an ill-fated mortgage securities investment called Abacus 2007-AC1. REUTERS/Lucas Jackson (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 15, 2013. Jury selection will begin today in the civil fraud case against Tourre, 34, who the SEC says misled investors in an ill-fated mortgage securities investment called Abacus 2007-AC1. REUTERS/Lucas Jackson (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 15, 2013. Jury selection will begin today in the civil fraud case against Tourre, 34, who the SEC says misled investors in an ill-fated mortgage securities investment called Abacus 2007-AC1. REUTERS/Lucas Jackson (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 15, 2013. Jury selection will begin today in the civil fraud case against Tourre, 34, who the SEC says misled investors in an ill-fated mortgage securities investment called Abacus 2007-AC1. REUTERS/Lucas Jackson (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 15, 2013. Jury selection will begin today in the civil fraud case against Tourre, 34, who the SEC says misled investors in an ill-fated mortgage securities investment called Abacus 2007-AC1. REUTERS/Lucas Jackson (UNITED STATES - Tags: CRIME LAW BUSINESS)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 15, 2013. Jury selection will begin today in the civil fraud case against Tourre, 34, who the SEC says misled investors in an ill-fated mortgage securities investment called Abacus 2007-AC1. REUTERS/Lucas Jackson (UNITED STATES - Tags: CRIME LAW BUSINESS TPX IMAGES OF THE DAY)

Former Goldman Sachs bond trader Fabrice Tourre arrives at the Manhattan Federal Court in New York, July 15, 2013. Jury selection will begin today in the civil fraud case against Tourre, 34, who the SEC says misled investors in an ill-fated mortgage securities investment called Abacus 2007-AC1. REUTERS/Lucas Jackson (UNITED STATES - Tags: CRIME LAW BUSINESS)

The logo of Abacus Federal Savings Bank is seen on Bowery Street in New York, May 31, 2012. Abacus Federal Savings Bank, which caters to Chinese immigrants in and around New York City, has been charged with selling fraudulent mortgage loans to Fannie Mae in a 184-count indictment. REUTERS/Andrew Burton (UNITED STATES - Tags: BUSINESS CRIME LAW LOGO)

The logo of Abacus Federal Savings Bank is seen on Bowery Street in New York, May 31, 2012. Abacus Federal Savings Bank, which caters to Chinese immigrants in and around New York City, has been charged with selling fraudulent mortgage loans to Fannie Mae in a 184-count indictment. REUTERS/Andrew Burton (UNITED STATES - Tags: BUSINESS CRIME LAW LOGO)

A woman enters a branch of Abacus Federal Savings Bank on Bowery Street in New York, May 31, 2012. Abacus Federal Savings Bank, which caters to Chinese immigrants in and around New York City, has been charged with selling fraudulent mortgage loans to Fannie Mae in a 184-count indictment. REUTERS/Andrew Burton (UNITED STATES - Tags: BUSINESS CRIME LAW)

People walk past a branch of Abacus Federal Savings Bank on Bowery Street in New York, May 31, 2012. Abacus Federal Savings Bank, which caters to Chinese immigrants in and around New York City, has been charged with selling fraudulent mortgage loans to Fannie Mae in a 184-count indictment. REUTERS/Andrew Burton (UNITED STATES - Tags: BUSINESS CRIME LAW)

A student uses an abacus as she takes part in a national UCMAS (Universal Concept of Mental Arithmetic System) competition in Khartoum March 26, 2011. REUTERS/Mohamed Nureldin Abdallah (SUDAN - Tags: EDUCATION SOCIETY)

A student uses an abacus as he takes part in a national UCMAS (Universal Concept of Mental Arithmetic System) competition in Khartoum March 26, 2011. REUTERS/Mohamed Nureldin Abdallah (SUDAN - Tags: EDUCATION SOCIETY)

A student uses an abacus as she takes part in a national UCMAS (Universal Concept of Mental Arithmetic System) competition in Khartoum March 26, 2011. REUTERS/Mohamed Nureldin Abdallah (SUDAN - Tags: EDUCATION SOCIETY)

Jamella, 8, counts with an abacus at South Los Angeles Learning Center in Los Angeles, California March 16, 2011. The center is run by School on Wheels, which uses volunteers to tutor homeless children in shelters, parks, motels, and two centers. There has been a surge in the number of homeless children in Los Angeles in the last five years, due to persistent unemployment and mounting foreclosures. REUTERS/Lucy Nicholson (UNITED STATES - Tags: EDUCATION SOCIETY)

An elementary schoolgirl takes part in an abacus contest in Tokyo May 19, 2010. About 100 students from American schools in U.S. military bases in Japan participated in the contest which made use of the soroban, a traditional Japanese calculating tool. REUTERS/Kim Kyung-Hoon (JAPAN - Tags: EDUCATION SOCIETY)

An elementary schoolgirl takes part in an abacus contest in Tokyo May 19, 2010. About 100 students from American schools in U.S. military bases in Japan participated in the contest which made use of the soroban, a traditional Japanese calculating tool. REUTERS/Kim Kyung-Hoon (JAPAN - Tags: EDUCATION SOCIETY)

An elementary schoolboy takes part in an abacus contest in Tokyo May 19, 2010. About 100 students from American schools in U.S. military bases in Japan participated in the contest which made use of the soroban, a traditional Japanese calculating tool. REUTERS/Kim Kyung-Hoon (JAPAN - Tags: EDUCATION SOCIETY)

An elementary schoolgirl takes part in an abacus contest in Tokyo May 19, 2010. About 100 students from American schools in U.S. military bases in Japan participated in the contest which made use of the soroban, a traditional Japanese calculating tool. REUTERS/Kim Kyung-Hoon (JAPAN - Tags: EDUCATION SOCIETY)

A girl attends lessons at a temporary school building in earthquake-hit Daba, Sichuan province December 15, 2008. China's earthquake zone of Sichuan can expect US$510 million of World Bank (WB) loan in January next year, said visiting WB Group President Robert B. Zoellick here on Sunday, Xinhua News Agency reported. REUTERS/Christina Hu (CHINA)

Sun Xiuling adds up the the cost of a meal with an abacus at Yuebin Restaurant located in the Cuihua Hutong (Lane) of Beijing November 17, 2008. The restaurant, opened in 1980 with 1,000 yuan ($146), is China's first privately run restaurant after the Cultural Revolution came to an end in 1976, according to Xinhua News Agency. REUTERS/Jason Lee (CHINA)