What is a Decimal Point?
A dot written in a decimal number to indicate where the place values change from whole numbers to decimal fractions
A decimal point is a dot (.) used to separate the whole number part of a number from the fractional part, if there is one. It tells us where the decimal part begins.
For example, in 3.5, the 3 is the whole number, and the .5 shows that there are 5 tenths. In 7.0, the decimal point is there, but the number still represents a whole value.
Here’s how it works:
- 4.0 means four exactly—no fractional parts
- 2.75 means 2 wholes and 75 hundredths
- 0.1 means one tenth (or 1 out of 10)
The digits to the right of the decimal point get smaller by powers of 10:
- The first place is tenths (0.1)
- The second place is hundredths (0.01)
- The third place is thousandths (0.001)
We use decimal points in everyday life all the time:
- Money: $5.99 means 5 dollars and 99 cents
- Measurement: 2.5 inches means 2 whole inches and half an inch more
When Do Students Start Using Decimal Points?
Most students are introduced to decimal points as soon as they begin learning about decimals,usually in upper elementary grades.
Grades 3–4 – Introduction to Decimal Points
Students learn that the decimal point separates whole numbers from parts of a whole. They use money, number lines, and grids to visualize decimals.
Grade 5 – Operations with Decimals
Students practice adding, subtracting, multiplying, and dividing with decimals. They learn to line up decimal points and understand their place value.
Grades 6–7 – Applying Decimals in Real-World Problems
Students use decimal points in advanced applications such as percentages, conversions, and multi-step word problems.
