Lesson 1.

Metric system

The most common units of measure in the metric system are kilometers (km), meters (m) and centimeters (cm).  The table below shows the relationship between the metric units.

Metric table - length

If we take 1 meter as the basic unit, we see the relationship between the metric units. The blue-shaded boxes show that 1 meter equals 10 dm, 100 cm and 1000 millimeters. The difference between each place is 10 or one zero.

1m = 10dm

1dm = 10cm

1cm = 10 mm

Examples

How many centimeters are 6.5 kilometers? We can use the metric table to help us find the answer. Place 6 in the km place and 5 in the next place to the right.

 Fill the places up to cm with zeros. Now you see that 6.5 km = 650 000 cm.

How many kilometers are 250 m? Put 250 meters in the table, as shown below.

We see that the number does not reach the km place, which means that 250 m is less than 1 km. Place a 0 in the km place and a decimal marker between km and hm. 
The answer is  250 m = 0.250 km. 

Practice this method and try Quiz 1 on Units of measure. Remember to use the Checklist to keep track of your work.