Metric Math Problems, Solutions and Explanations

Why Should My Child Know the Metric System?

American students learn how to work with the United States Customary System - also known as standard units - which is the primary system of measurement used in the U.S. Standard units include inches, yards, pounds and miles. However, students will also work with metric units in many math and science classes. Some metric units of measure, like liters and centimeters, are frequently seen in daily life.

Conversions are a large part of working with different systems of measurement. To convert, your child will need a conversion chart. For instance, one inch is the same as 2.54 centimeters. Using the information from the chart, your child can create a proportion to calculate other conversions.

For example, to calculate how many centimeters are in three inches, use the following proportion: 1/ 2.54 = 3/x. You would cross multiply to solve for x by multiplying 2.54 (the denominator) from the first fraction with the 3 (numerator) of the second fraction, which gives you x = 7.62 cm.

Metric Math Problems

Conversion Chart

1 yard (yd) = 0.9144 meters (m)

1 gallon (gal) = 3.785 liters (l)

1 pound (lb) = 0.4536 kilograms (kg)

1 mile (mi) = 1.609 kilometers (km)

Sample Problems

1. Tim needs to buy 100 yards of fencing to surround his backyard, but the store only sells the fencing in meters. How many meters does Tim need to buy to get 100 yards?

Remember that any conversion problem can be solved by creating a proportion. For this problem, the proportion should look like this: 1/0.9144 = 100/x. After solving x, you will find that 100 yards = 91.44 meters.

2. Mandy bought three gallons of milk. How many liters is that?

The proportion looks like this: 1/3.785 = 3/x. Three gallons is equal to 11.355 liters. Often, when converting, your child will have to estimate the final answer. Typically, it is acceptable to round to the nearest thousandths place.

3. Amanda's dog weighs 80 pounds. How many kilograms does her dog weigh?

Amanda's dog weighs about 36.288 kg. The proportion used is 1/0.4536 = 80/x.

4. If your school is 1.5 miles away, how many kilometers is that?

The school is about 2.414 kilometers away. The conversion proportion should look like this: 1/1.609 = 1.5/x.