Decimals

A decimal is a number with a dot in it called a decimal point. The decimal point separates whole numbers from parts of a whole. For example, 3.5 means three and a half. Decimals help us write numbers that are not whole, like money or measurements.

Place Value

In a decimal, the digits to the left of the dot are whole numbers. The digits to the right show parts smaller than one. The first place after the dot is tenths, the next is hundredths, and so on. For example, in 2.75, the 7 is in the tenths place and the 5 is in the hundredths place.

Two hands with ten fingers, just like our number system.
Two hands with ten fingers, just like our number system. (Maher27777 / Wikimedia Commons)

Using Decimals

We see decimals every day, especially with money. A dollar and fifty cents is written as $1.50. Decimals are also used in sports, science, and cooking. They help us measure things exactly, like the length of a pencil or the weight of an apple.

Fun Facts

  • The word decimal comes from the Latin word for ten.
  • Pi is a famous decimal that starts with 3.14 and never ends.
  • Decimals and fractions can show the same value, like 0.5 and 1/2.

Did You Know?

In some countries, people use a comma instead of a dot as the decimal point.