Division and multiplication with decimals

(a) 3.6/0.2

we work this out by multipling both numbers untill they are no longer decimals.

3.6 x 10 = 36

0.2 x 10 = 2

36/2 = 18    so, 3.6/0.2 = 18

Simple really :)

Try it yourself with these numbers:

(1) 42/0.2

(2) 0.2/0.04

Answers on the next card.

(1) 42 x 10 = 420

     0.2 x 10 = 2

420/2 = 210

(2) 0.2 x 100 = 20

     0.04 x 100 = 4

20/4 = 5

Multiplying decimals is a bit like dividing, we can times them to get them to a whole number - however, unlike dividing we have to divide the answer back again.

1) 3.6 x 0.2

3.6 x 10 = 36

0.2 x 10 = 20

36 x 20 = 72

72/100= 7.2

so, 3.6 x 0.2 = 7.2