Question

Xiao’s teacher asked him to rewrite the sum 60+90 as a product of GCF of two numbers and A sum . xiao wrote 3(20+30.what mistake did xiao make ? How should he have written the sum

Answer 1

The first thing we must do for this case is find the factors of each of the numbers.

We have then:

60: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60

90: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90

Therefore the GCF is given by:

$GFC = 30$

So, by rewriting the sum we have:

$60 + 90 = 30 (2 + 3)$

The error is not having written the GCF multiplying.

Answer:

Xiao did not write the sum as the product of GCF and the sum of two numbers.

The correct expression is:

$60 + 90 = 30 (2 + 3)$