Fractions, decimals and percentage conversions

On the non-calculator paper, leaping to the final fraction (e.g. straight to $\tfrac{15}{4}$) with no improper-fraction or cancelling step shown loses method marks — and can hide errors.

When told to "use algebra to show" a recurring decimal equals a fraction, a non-algebraic answer scores at most 1 mark.

Choosing $x$ and $100x$ (or other mismatched powers) so the recurring tails do NOT cancel — you must pick powers whose decimal parts are identical before subtracting.

Percentage → decimal divides by $100$ ($45\% = 0.45$); decimal → percentage multiplies by $100$ ($0.45 = 45\%$). Reversing these — writing $45\% = 4500$ or $0.45\%$ — is a frequent slip. Move the point two places and check the size looks sensible.

A fraction in lowest terms terminates only when its denominator has just $2$s and $5$s as prime factors; otherwise it recurs. So $\tfrac{3}{8}$ terminates but $\tfrac{1}{3}$ and $\tfrac{5}{6}$ recur. Rounding a recurring decimal and treating it as exact loses accuracy.