Question

How many decimetres are equal to 1 metre?

Answer 1

Hint: We know that metre (m) and decimetre (dm) are units of length and what the relationship between them is. The relationship is 1 dm = ${{10}^{-1}}$ m or 1 dm = 0.1 m. Using this relationship, we can find how many decimetres are equal to 1 metre.

Complete step-by-step solution:
We know very well that metre (m) and decimetre (dm) are units of length.
Also, we know that in the International System of Units (SI) system, the length of the base unit is the metre (symbol m), which is also the fundamental unit of length. We must know that metre is defined in terms of the speed of light which is about 300 million metres per second. Decimetre, centimetre, millimetre are the derived units of length.
We can see that the relationship of these units with a metre is given by the following table,

1 decimetre (dm)	${{10}^{-1}}$ metres
1 centimetre (cm)	${{10}^{-2}}$ metres
1 millimetre (mm)	${{10}^{-3}}$ metres
1 micrometre ($\text{ }\!\!\mu\!\!\text{ m}$)	${{10}^{-6}}$ metres
1 nanometre (nm)	${{10}^{-9}}$ metres

We can clearly see that the relationship between a metre and a decimetre is
1 dm = 0.1 m
Hence, we can also say that 1 m = 10 dm.
Hence, we can say that 10 decimetres are equal to 1 metre.

Note: We must remember the relationship between different units to be able to solve this question. We must also not confuse between decimetre, represented as dm and decametre, which is represented as dam. The relationships are 1 dm = 0.1 m, and 1 dam = 10 m.