Explain how to use properties of addition

When we add two or more whole numbers, their sum is the same regardless of the order of the addends. The sum of both 2 + 4 and 4 + 2 is 6. That means, we can add whole numbers in any order. When three or more numbers are added, the sum is the same regardless of the grouping of the addends.

6.9

step-by-step explanation:

simple math really

6 1/2 times 0.6 = 3.9

but if you are just doing 6 and not 6 1/2 then the answer is 3.6