Unit conversion, step by step
Once a child knows what a meter or a kilogram is, the next skill is moving between the units.
The question
9150 mm = ________ cm
150 mm = ? cm
mm → cmbigger unit, smaller number
1 cm =10 mm
150 ÷ 10 =15
15 cm
- One cm is bigger than one mm, and it takes FEWER of a big thing to make the same amount. So the number has to get smaller — which means dividing.
- There are 10 mm in one cm, so that is the number to divide by.
- 150 ÷ 10 = 15, so 150 mm is 15 cm. Check the direction held: the number got smaller, which is what a bigger unit does.
How it works.
- 01
One cm is bigger than one mm, and it takes FEWER of a big thing to make the same amount. So the number has to get smaller — which means dividing.
- 02
There are 10 mm in one cm, so that is the number to divide by.
- 03
150 ÷ 10 = 15, so 150 mm is 15 cm. Check the direction held: the number got smaller, which is what a bigger unit does.