True or False: A decimeter, a centimeter and a millimeter are all smaller than a meter.

Step-by-step explanation:

Convert all the units to metres for compariosn.

By metric conversion,

1 decimetre = 0.1 metre

1 centimetre = 0.01 metre

1 millimetre = 0.001 metre

Based on the above conversions, a decimeter, a centimeter and a millimeter are all smaller than a meter. Therefore the given statement is true.