. Grade 4, Illustrative icon
Task

Multiples of nine

Illustrative MathematicsVaries

This task examines the interesting fact that when a number is divisible by 9 then the sum of its digits is also divisible by 9. Only one and two digit numbers are examined here. A natural extension of this activity would be to see if this pattern remains true for three digit or larger numbers. At this age, students are multiplying large numbers by a single digit number and so they could be encouraged to pursue further this interesting fact about the sum of the digits in numbers divisible by 9.

You must log inorsign upif you want to:*

*Teacher Advisor is 100% free.