The idea, step by step
Read the denominator as a place name
A fraction with denominator ten counts tenths. A fraction with denominator one hundred counts hundredths. This lets us move directly between fraction and decimal notation.
Three tenths is 0.3. Three hundredths is 0.03. The denominator tells which column receives the digit.
Make a useful equivalent fraction
For a familiar fraction such as one half, rename it in tenths or hundredths first. One half is five tenths, so it is 0.5.
One quarter is twenty-five hundredths, so it is 0.25. Use equal strips or a hundred-grid to justify the conversion; the amount must stay unchanged.
A common trap
Writing as 0.7.
Instead: Seven hundredths needs two places after the point: 0.07. The zero shows there are no tenths.
See the thinking
Convert a fifth
Write as a decimal.
- Multiply numerator and denominator by 2 to make tenths.
- .
- Four tenths is written 0.4.
Convert three quarters
Write as a decimal.
- Each quarter is twenty-five hundredths.
- Three groups of twenty-five are seventy-five.
- Three quarters equals seventy-five hundredths.
Check your understanding
What decimal equals ?
Show answer
One quarter equals twenty-five hundredths, .
Your turn
6 questions · 9 marks · Work at your own pace.
Read the questions online
- Write as a decimal.1 mark
- Write as a decimal.1 mark
- Write 0.23 as a fraction with denominator 100.1 mark
- Write 0.8 as a fraction in tenths and in hundredths.2 marks
- Write and as decimals.2 marks
- Which is larger, or 0.35? Explain.2 marks
Read the worked solutions
Equivalent correct methods earn the corresponding marks. Include units where asked.
- Write as a decimal.1 mark
The fraction counts three tenths.
- Write as a decimal.1 mark
Seven belongs in the hundredths place.
- Write 0.23 as a fraction with denominator 100.1 mark
The amount is twenty-three hundredths.
- Write 0.8 as a fraction in tenths and in hundredths.2 marks
Eight tenths contain eighty hundredths.
- Write and as decimals.2 marks
One half is five tenths; one quarter is twenty-five hundredths.
and . - Which is larger, or 0.35? Explain.2 marks
; forty hundredths is more than thirty-five hundredths.
Curriculum reference & lesson scope
Australian Curriculum v9 and SA Curriculum Mathematics
Tenths/hundredths; representations; notation; fraction connections.
Official curriculum source ↗