Task# Threatened and Endangered

Illustrative MathematicsVaries

This task addresses 4.NBT.1 in that in requires students to understand multiplying and dividing whole numbers by powers of 10. It also addresses 4.OA.1 since it helps students push their understanding of multiplication from a 3rd grade understanding of repeated addition to a 4th grade understanding that we can also use multiplication to understand 'times as many' comparison problems. A tape-diagram may be helpful in this problem. Though this task seems straightforward, it actually requires students to work backwards from the known value that is 'ten times as many.'