Decimals
Understand tenths, hundredths and how decimals connect to fractions and place value!
What Are Decimals?
A decimal is another way to write fractions that have denominators of 10, 100, 1000, etc. The decimal point (.) separates the whole number part from the fractional part.
3.7
3
Whole number
.
Decimal point
7
Tenths
This means 3 ones and 7 tenths, or 3 and 7⁄10
Tenths and Hundredths
Tenths
3⁄10 = 0.3
1 digit after the decimal point
Hundredths
7⁄100 = 0.07
2 digits after the decimal point
| Fraction | Decimal | How to say it |
|---|---|---|
| 1⁄10 | 0.1 | one tenth |
| 5⁄10 = 1⁄2 | 0.5 | five tenths (one half) |
| 1⁄100 | 0.01 | one hundredth |
| 25⁄100 = 1⁄4 | 0.25 | twenty-five hundredths (one quarter) |
| 75⁄100 = 3⁄4 | 0.75 | seventy-five hundredths (three quarters) |
Place Value with Decimals
Each digit in a decimal number has a place value. The further right a digit is, the smaller its value.
| Tens | Ones | . | Tenths | Hundredths |
|---|---|---|---|---|
| 1 | 4 | . | 3 | 6 |
14.36 means:
1 ten + 4 ones + 3 tenths + 6 hundredths = 10 + 4 + 0.3 + 0.06
Decimals on a Number Line
Decimals fit between whole numbers on a number line.
Between 0 and 1, there are 10 equal steps of 0.1 (one tenth).
💡 Comparing Decimals
Compare from left to right, just like whole numbers: 0.6 > 0.4 because 6 tenths is more than 4 tenths.
Watch out: 0.5 = 0.50. Adding a zero at the end does NOT change the value!
Knowledge Check
Choose the correct answer for each question. Questions get harder as you go!
1. What is 1⁄10 written as a decimal?
2. What does the 5 represent in 2.5?
3. Which decimal is the same as one half (1⁄2)?
4. Which is bigger: 0.7 or 0.3?
5. What is 0.25 as a fraction?
6. What is the value of the digit 4 in 12.43?
7. Put these decimals in order from smallest to largest: 0.9, 0.09, 0.45
8. What is 3.2 + 0.5?
9. A ribbon is 1.85 metres long. What is the value of the 8?
10. Which of these is true?
Key Concepts Summary
- ●Decimals are another way to write fractions with denominators of 10, 100, etc.
- ●The first digit after the decimal point is tenths, the second is hundredths.
- ●Compare decimals by looking at place value from left to right.
- ●Adding a trailing zero does not change the value (0.5 = 0.50).