Billy is 154 centimeters tall. What is Billy's height in decimeters?

We have to first find relation between centimeter and decimeter here.

Centimeter and decimeter can be related as follows:

10 centimeter = 1 decimeter

or

1 centimeter = 0.1 decimeter

Now converting 154 centimeter into decimeter using unitary method:

1 centimeter = 0.1 decimeter

154 centimeter = 0.1 * 154 decimeter

Answer:

154 centimeter = 15.4 decimeter

15.4 is the answer to your question