Topics › KS3 › Number

Fractions, decimals & percentages

fdp-01 Present from here

Write $\frac{3}{5}$ as a decimal.

Option A: $0.6$

Option B: $0.35$

Option C: $0.3$

Option D: $1.\dot{6}$

Answer and misconceptions

Option A: $0.6$ ✓ Correct

Option B: $0.35$ ✗
Writes numerator and denominator after the pointThinks 3/5 is written as 0.35, putting the digits side by side.

Option C: $0.3$ ✗
Reads the numerator as tenthsThinks 3 out of anything is 0.3, ignoring the denominator.

Option D: $1.\dot{6}$ ✗
Divides the denominator by the numeratorHas worked out 5 ÷ 3 instead of 3 ÷ 5.
fdp-02 Present from here

Write $0.07$ as a percentage.

Option A: $70\%$

Option B: $7\%$

Option C: $0.07\%$

Option D: $0.7\%$

Answer and misconceptions

Option A: $70\%$ ✗
Ignores the zero placeholderReads 0.07 as if it were 0.7, so gives 70%.

Option B: $7\%$ ✓ Correct

Option C: $0.07\%$ ✗
Adds a % sign without multiplying by 100Thinks a decimal becomes a percentage just by writing % after it.

Option D: $0.7\%$ ✗
Multiplies by 10 instead of 100Has moved the digits only one place.
fdp-03 Present from here

Write $35\%$ as a fraction in its simplest form.

Option A: $\frac{7}{20}$

Option B: $\frac{1}{35}$

Option C: $\frac{3}{5}$

Option D: $\frac{7}{2}$

Answer and misconceptions

Option A: $\frac{7}{20}$ ✓ Correct

Option B: $\frac{1}{35}$ ✗
Thinks a percentage means 1 out of that numberReads 35% as 1/35.

Option C: $\frac{3}{5}$ ✗
Splits the digits into numerator and denominatorUses the digits 3 and 5 as the fraction 3/5.

Option D: $\frac{7}{2}$ ✗
Thinks per cent means out of 10Has written 35/10 and simplified it to 7/2.
fdp-04 Present from here

Which of these is the largest?

Option A: $0.58$

Option B: $\frac{6}{11}$

Option C: $6\%$

Option D: $0.6$

Answer and misconceptions

Option A: $0.58$ ✗
Compares decimals as whole numbersThinks 0.58 > 0.6 because 58 > 6.

Option B: $\frac{6}{11}$ ✗
Writes a fraction's digits after a decimal pointReads 6/11 as 0.611, which beats 0.6, but 6/11 ≈ 0.55.

Option C: $6\%$ ✗
Ignores the % sign when comparingReads 6% as 6, but 6% = 0.06.

Option D: $0.6$ ✓ Correct
fdp-05 Present from here

Write $\frac{1}{8}$ as a percentage.

Option A: $18\%$

Option B: $8\%$

Option C: $12.5\%$

Option D: $1.25\%$

Answer and misconceptions

Option A: $18\%$ ✗
Writes the numerator and denominator digits togetherTurns 1/8 into 18%.

Option B: $8\%$ ✗
Uses the denominator as the percentageThinks 1 out of 8 means 8%.

Option C: $12.5\%$ ✓ Correct

Option D: $1.25\%$ ✗
Multiplies the decimal by 10 instead of 100Has 1/8 = 0.125 correctly but then multiplies by 10.