Question

Which method do you prefer to use to find sums- count by tens and ones, use compatible numbers, or use friendly numbers and adjust? Explain why.

Answer 1

I prefer to use compatible numbers to find sums, as I find this tends to be a faster and more efficient method through which to get to the answer.

Answer 2

I prefer to use compatible numbers because by using this method it is easier to make a sum mentally. This is true because compatible numbers are close in value to the actual numbers. For a better understanding, let's take an example:

Suppose you have two numbers, namely 640 and 40. These two numbers are compatible for division because:

64 ÷ 4 = 16

So, we have used mental arithmetic to solve a more complex problem.