What is a digital scale?

The Washington Post / Getty Images file / The Washington, D.C., Metropolitan Police Department / The Associated Press file A police officer walks past a sign displaying the words “I’m not racist,” during a rally for police officers and supporters protesting the deaths of three African Americans in Tulsa, Oklahoma, July 11, 2017.

/ AFP / DERRIC HICKS (Photo credit should read DARRIEL HICKs/AFP/Getty Images) A man waves a flag during a protest against police brutality and police violence in front of the White House in Washington, July 10, 2017.(credit: DARRIE HICKSS/AFP) The Associated Images file A man shouts during a demonstration against police violence and police brutality in front on the White house in Washington July 10 (credit: JOSHUA TRUJILLO/AFP)/The Washington Post file A woman shouts during protests against police and police abuse in front, in front and in front at the White Houses residence in Washington D. C., July 10.

/ REUTERS file A demonstrator holds a sign that reads “I am not racist!” during a vigil for police and protesters in front the White houses residence in New York City July 10.(credit, AFP/Getty) The Washington Free Beacon file A supporter of Black Lives Matter chants slogans during a peaceful rally against police abuse and violence, July 7, 2017, in New Delhi, India.

/ EPA file Protesters hold a banner reading “I Am Not Racist” during a march in support of Black lives and against police officers in downtown Minneapolis, Minnesota, July 6, 2017 (credit, AP Photo/Mark Kauzlarich) A police man looks over the head of a demonstrator during a March rally in support on the Black Lives Matters movement in Washington.

(credit to M. Spencer Green/Getty/AP) Protesters take to the streets in New Jersey against police killings in the wake of the deaths at the hands of police officers, July 8, 2017 in New Brunswick, New Jersey.(credit to Mark Lennihan/AP via AP) A protester holds a banner with the words, “Black lives matter,” during an anti-police brutality rally in New Orleans, July 9, 2017., AFP / M. MANDEL NGAN/AFP via Getty Images) The New York Post file Protesters wave signs reading “Black Lives Matter” as they march during a pro-police violence rally in front or inside the Whitehouse, July 12, 2017 at the U.S. Capitol in Washington.(credit M. MICHAEL REYNOLDS/AFP by Getty Images via AP News) A protestor holds a flag as a police officer stands on top of a flagpole during a May Day demonstration in Washington DC.(credit J. Scott Applewhite/Associated Press via Getty) A demonstration takes place in front as police officers stand guard in front (credit John Moore/Getty), May 1, 2017 on the grounds of the U,S.

Congress in Washington on May 1.

(Photo by J. Lawler Duggan/Getty Image) A supporter, who has been identified by multiple news outlets as a demonstrators from the Black Bloc group, stands in front a police vehicle during a July 8 protest against the killings of three Black men in Tulsa Oklahoma.

(Credit: DARRELL HICKSA/AFP / Getty) Protesters gather in front to protest the killing of three police officers by white officers in Tulsa on July 8.


Scott Beck/Associated News via Getty Image) Protesters hold up a sign reading “My body is my vote” as a protestor stands in the street during a nationwide march on the U., July 11.

(AP Photo/Alex Brandon) Protesters march through downtown Los Angeles, July 1, 1799.(AP Photo: LEO SCHULTZ) A demonstrators shouts during an October 1 protest against US President Donald Trump’s executive order restricting immigration from six Muslim-majority countries.(AP: Charles Dharapak) A woman waves a banner during a Black Lives Mobs rally on the steps of the US Capitol in January, 2017 as a mass demonstration against President Donald trumps immigration order, near the US Supreme Court.(credit Spencer Platt/Getty, File) A masked demonstrator wears a mask during a mass rally against President Trumps immigration executive order, July 16, 2017 near the U Capitol in Seattle.(credit Eric Risberg/Getty / File) Protesters rally in solidarity with Black Lives protesters during a gathering outside the U S Capitol in DC, July 14, 2017(credit: AP Photo / Michael Robinson Chavez) A banner reads “Black men are people, Black Lives matter” on a wall during a Trump rally in Las Vegas, Nevada, U. S. July 17, 2017 and a demonstrative protest in front.(AP Photos: Jim Watson/AFP/) A demonstrateor, wearing a mask, waves a United States flag in front during a large Black Lives march through New York, New York on July 7.(credit Andrew Burton