Number Foundations practice questions — GCSE Maths

$0.15 \times 80 = 12$.

$12 \div 4 = 3$ and $2 \times 3 = 6$, then $3 + 6 = 9$.

The third decimal digit is $8 \ge 5$, so round the second decimal up: $3.728 \approx 3.73$.

$24 = 2^3 \cdot 3$ and $36 = 2^2 \cdot 3^2$.

Shared primes at their lowest powers: $2^2$ and $3$.

$\text{HCF} = 4 \cdot 3 = 12$.

$\dfrac{3}{4} \times 100\% = 75\%$.

$3 \times 4 = 12$, then $2 + 12 = 14$.

The first two significant figures are "$28$". The next digit is $5 \ge 5$, so round up: $29\,000$.

$49.2 \approx 50$ and $5.1 \approx 5$, so the estimate is $50 \times 5 = 250$.

$6 = 2 \cdot 3$ and $8 = 2^3$.

Highest powers: $2^3$ and $3$.

$\text{LCM} = 8 \cdot 3 = 24$.

$51 = 3 \cdot 17$, $57 = 3 \cdot 19$, $63 = 7 \cdot 9$.

$59$ has no factor up to $\sqrt{59} < 8$, so $59$ is prime.