Question

Explain how to find 4x80

Answer 1

4* 80 =

4*8 = 32

4*8 0 = 32 0

4* 80 = 320

Answer 2

For this case we have the following expression:

$4 * 80$

To solve the following steps:

Step 1:

We rewrite the biggest multiplication factor, that is, 80:

$80 = 8 * 10$, that is, ten times the number eight results in eighty.

So, we have:

$4 * 8 * 10$

Step 2:

We apply associative property of multiplication, which states:

$a * b * c = a * (b * c) = (a * b) * c = b * (a * c)$

If we have:

$a = 4\\b = 8\\c = 10$

We apply:

$(a * b) * c = (4 * 8) * 10$

So, first solving the product in parentheses, we have four times eight to thirty-two.

$(a * b) * c = (4 * 8) * 10 = 32 * 10$

In this way we can multiply by 10 which is easier.

We know that to every number multiplied by 10, a zero must be added.

$(4 * 8) * 10 = 32 * 10 = 320$

Answer:

$(4 * 8) * 10 = 32 * 10 = 320$