How do you multiply fractions with a whole number

You put the whole number on top of 1, it doesnt change its value. then you simplify across like in a butterfly only if needed then you multiply across from left to right.

When multiplying fractions and whole numbers, you either turn the fraction into a decimal, or the whole number into a fraction.

For example, the solution for 2/5(8) can be found by turning 2/5 into a decimal (0.4) and multiplying that by 8, or by turning 8 into a fraction (8/1) and multiplying those together.
You will get 3.2 and 16/5. 16/5 can be simplified to be 3 1/5, or 3.2. As you can see, either method works and will give you the same answer.