How long is a hammer?
20 millimeters 20 centimeters 20 kilometers 20 meters
Select the best estimate.
Measurements are written with both a number and a unit. The unit comes after the number. The unit shows what the number means.
When you are using metric units, length can be written with units of millimeters, centimeters, meters, or kilometers. One meter contains 100 centimeters or 1,000 millimeters. So, 1 meter is larger than 1 centimeter, and 1 centimeter is larger than 1 millimeter.
The tip of the pencil shown here is only 1 millimeter wide, but the pencil is about 16 centimeters long.
A red fox is about 1 meter long. The Sydney Harbour Bridge in Australia is about 1,000 meters, or 1 kilometer, in length.
The best estimate for the length of a hammer is 20 centimeters.
20 millimeters is too short. 20 meters and 20 kilometers are too long.