Decimals are another way to write fractions with 10 or 100 on the bottom. The decimal point separates whole numbers from parts: the first place after it is tenths, the second is hundredths.
What your child will learn
- Write tenths and hundredths as decimals
- Say the value of each digit in a decimal
- Compare decimals with one and two decimal places
- Add and subtract tenths
Longer is not bigger
Many children think 0.35 is bigger than 0.4 because 35 is bigger than 4. Give both numbers the same number of decimal places — 0.40 and 0.35 — and it is clear that 0.4 is bigger.
Adding tenths
0.7 + 0.5 is 7 tenths plus 5 tenths, which makes 12 tenths. Ten tenths make one whole, so the answer is 1.2 — not 0.12.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. Which decimal is the same as 8/10?
- 0.08
- 8.10
- 0.8
- 8.0
Show answer
Answer: 0.8. 8/10 means 8 tenths, which is written 0.8.
2. Which decimal is the same as 6/10?
- 6.0
- 6.10
- 0.06
- 0.6
Show answer
Answer: 0.6. 6/10 means 6 tenths, which is written 0.6.
3. What is the value of the 7 in 1.7?
- 7 tenths
- 7 hundredths
- 7 tens
- 7 ones
Show answer
Answer: 7 tenths. In 1.7, the 7 is in the tenths place, so it is worth 7 tenths.
Tips for grown-ups
- Money is a ready-made decimal: 3.50 means 3 wholes and 50 hundredths.
- Measure things in metres with a tape measure and read the decimals aloud.