each box has 10 pencils . how many pencils do 3 boxes have ?

10 * 3 = ?

Count by 10's three times.

To find out how many pencils 3 boxes have, you can multiply the number of pencils in one box by the number of boxes.

In this case, each box has 10 pencils, so we can calculate:

10 pencils/box * 3 boxes = 30 pencils

Therefore, 3 boxes have a total of 30 pencils.