pieces of chalk are stacked in a pile. part of the pile is shown. the bottom row has 15 pieces of chalk, and the top row has 6 pieces of chalk. each row has on less piece of chalk than the row below it. how many pieces of chalk are in the pile?
To answer the question, you need to count backwards from 15 to 6 and add up the pieces of chalk. 15+14+13+12+11+10+9+8+7+6=105. That means there are 105 pieces of chalk in the pile. Hope this helps.