Why does 2x2=4 when 2+2=4 but 1x1 is 1 and 1+1=2? ?

Asoccer ball manufacturer wants to estimate the mean circumference of soccer balls within 0.1 in

Sue's average score for three bowling games was 162. in the second game, sue scored 10 less than in the first game. in the third game, she scored 13 less than in the second game. what was her score in the first game?

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?