Hold up your hands in front of you and count your fingers—TEN. That’s right—10. Remember that TEN and multiples of TEN are very important numbers in the metric system.

In ancient times, too, men held up a certain number of fingers to account for more than one object. Later on every king had his own way of measuring. A foot, for example, was the distance from the tip of the king’s big toe to the back of his heel or the distance of thirty-six barleycorns laid end to end. A pace was the distance he could cover in one stride, and the distance from the king’s nose to his outstretched fingertips was one yard.

As life became more complex and men began to travel, to trade goods, and to share their knowledge of the physical world around them, more precise ways for measuring distances and amounts of things became necessary. Because the English ruled the seas for so many years and traded in distant markets throughout the world, their terms for measuring quantities of goods were generally accepted everywhere. However, drams, quarts, and gallons; barrels, bushels, and bodges; firkins, pins, and puncheons proved to be awkward units of measure. When dividing one quantity by another it is difficult to come out with even amounts and the answers are often confusing.

In 1790 the French proposed a more satisfactory method for measuring and called it the metric system. It is based on the universally accepted decimal system. Many metric answers to problems are obtained by adding only a zero or moving a decimal point, much simpler than changing yards to feet and then to inches.

Most countries in the world today use the metric system. However, the United States, Ghana, Burma, Oman, South Yemen, Gambia, Liberia, and Sierra Leone use it not at all or only in a limited way. But even in most of these countries, doctors, druggists, and scientists use the metric system in their work every day. And, of course, in the Olympic Games distances are always measured in metric meters.

The next time you go to the grocery store look at the labels on some canned goods. Many cans will have their contents listed in both ounces and GRAMS or LITERS. A gram is a measure of weight in the metric system and a liter is a liquid measure. Clothing patterns in the United States now have dimensions listed in inches and their equivalent in metric centimeters. Although it takes considerable time to change all that a country measures, buys, and uses over to the metric system, it won’t be long until everyone in the world is using it. Many boys and girls who haven’t used the metric system before are already learning something about it in school.

On these pages you will find some examples of measuring to help you think and figure metrically.

When you were born you measured about 48 centimeters long or high. To find out how many centimeters high you are now, make a meter stick.

1. Place a narrow strip of cardboard next to the 10-centimeter ruler on this page and make a copy of it for your own ruler.

2. Next, find a flat, narrow piece of wood at least 40″ long and, using your 10-centimeter ruler, mark off 10 centimeters, 20 centimeters, and so on until you have a meter stick 100 centimeters long. (The word cent comes from the Latin word centum that means 100, and you already know that there are 100 cents in one dollar.)

3. Stand up straight with your back to the wall and have someone put a tiny pencil mark where your head reaches, then take your meter stick and measure how tall you have grown.

Measure the width of your stove, the height of the refrigerator, the distance from your front steps out to the sidewalk. With the centimeter ruler you can measure the length of a pencil, your comb, or the diameter of a cereal bowl. Long distances from city to city are measured in kilometers (1,000 meters).

When you become familiar with figuring sizes and distances in centimeters, meters, and kilometers, you can learn about—

weight of objects (milligrams, grams, kilograms)

liquid measure (milliliters, liters, kiloliters)

temperature (Centigrade—1º to 100º)

electricity (amperes)

Common Metric Prefixes and Quantities (See dictionary for additional sizes and quantities).

milli = 1/1,000

centi = 1/100

deci = 1/10

kilo = 1,000

meter = 39.37 inches

kilometer = 0.62 mile

liter = 1.057 quarts

gram = 0.035 ounce

Metric Sizes—Capacities—Weights—Distances


United States from coast to coast = 6,360 kilometers

home plate to 2nd base on a baseball diamond = 38.8 meters

pigeons’ speed in flight = 60–100 kilometers/hour


horse = 450 kilograms

baseball = 142 grams

75-pound child = 34,000 grams (34 kilograms)

one small and one medium-size safety pin = 1 gram

a nickel = 5 grams

twenty-pound bag of sugar = 9.09 kilograms

pound of butter = 454 grams


gallon of syrup = 3.785 liters

12-ounce can of soda water = .3549 liter


World Trade Center in New York City = 412 meters

Height of Khufa Pyramid in Egypt = 145 meters

Illustrated by Dick Brown