The idea, step by step
Say what each digit counts
Read 2.05 as two and five hundredths, or two point zero five. The zero holds the empty tenths place.
Writing 2.5 instead changes the amount to two and five tenths. Use a chart when a spoken decimal includes an empty place.
Compare like-sized units
Compare whole-number parts first, then tenths, then hundredths. If needed, write a zero in the hundredths place without changing the amount: 0.8 and 0.80 are equal.
The number with more digits is not automatically larger. Eighty hundredths is greater than nine hundredths, even though 0.09 has more displayed decimal digits than 0.8.
| Amount | Ones | Tenths | Hundredths |
|---|---|---|---|
| 0.8 | 0 | 8 | 0 |
| 0.09 | 0 | 0 | 9 |
A common trap
Thinking 0.09 is larger than 0.8 because 9 is larger than 8.
Instead: The digits count different-sized parts. Rename 0.8 as 0.80, then compare eighty hundredths with nine hundredths.
See the thinking
Keep an empty place
Write two and five hundredths as a decimal.
- Write 2 whole units before the point.
- There are no tenths, so put 0 in that place.
- Put 5 in the hundredths place.
Compare amounts
Which is greater, 4.08 or 4.8?
- Both amounts contain 4 wholes.
- The first has 0 tenths; the second has 8 tenths.
- Comparing tenths decides the order.
Check your understanding
Write nine hundredths as a decimal.
Show answer
There are no wholes or tenths; nine belongs in the hundredths place.
Your turn
6 questions · 8 marks · Work at your own pace.
Read the questions online
- Write nine hundredths as a decimal.1 mark
- Write 0.90 in words.1 mark
- Write three and four hundredths as a decimal.1 mark
- Which is greater, 6.07 or 6.7?1 mark
- Order 0.15, 0.51 and 0.05 from least to greatest.2 marks
- The chart has 2 ones, 0 tenths and 6 hundredths. A student writes 2.6. Correct the number and explain.2 marks
Read the worked solutions
Equivalent correct methods earn the corresponding marks. Include units where asked.
- Write nine hundredths as a decimal.1 mark
Put zero in the tenths place and nine in the hundredths place.
- Write 0.90 in words.1 mark
Nine tenths and zero extra hundredths equal ninety hundredths.
Ninety hundredths, or nine tenths. - Write three and four hundredths as a decimal.1 mark
Use 3 ones, 0 tenths and 4 hundredths.
- Which is greater, 6.07 or 6.7?1 mark
The whole parts match; seven tenths is more than zero tenths.
- Order 0.15, 0.51 and 0.05 from least to greatest.2 marks
Compare the tenths: zero, one and five.
- The chart has 2 ones, 0 tenths and 6 hundredths. A student writes 2.6. Correct the number and explain.2 marks
A zero is needed in the empty tenths place. Without it, the 6 counts tenths.
Curriculum reference & lesson scope
Australian Curriculum v9 and SA Curriculum Mathematics
Tenths/hundredths; representations; notation; fraction connections.
Official curriculum source ↗