Factoring the Divisor

When dividing, you can split up the divisor to make the question easier.
Let’s take a look at how and why this works.

126÷6 doesn’t seem that easy mentally.  If we split 6 into 2×3, it may help.

126 ÷ 2 = 63

63 ÷ 3 = 21

So 124 ÷ 6= 21

What we’ve done is 126 ÷ 2÷ 3 = 63

The groups of meaning for division can help explain why this works.factor divisor

124 split into 2 groups, then split each of these groups 3 times:

 

 

 

I think it would actually be easier to use the distributive property here, but teachers need to understand this principle if we ask students to actually think about division situations.  I’ve seen this strategy used by students, I think because doubling and splitting in half seem to be preferred strategies.

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