Top 11+ scorers in maths have one thing in common: fluent arithmetic. Not "they can work it out", but "they know it cold". Here's the foundation list every Year-5 child should have under control before tackling reasoning-heavy 11+ problems.
Number facts
Times tables to 12. Doubling and halving up to 100. Number bonds to 100. Decimal-fraction equivalents (½ = 0.5, ¼ = 0.25, etc.).
Operations
Column addition and subtraction. Short and long multiplication. Short division. Order of operations (BIDMAS). Practice now on number-operation questions to gauge fluency.
Fractions, decimals, percentages
Converting between all three. Finding fractions of amounts. Calculating simple percentages.
Time, money, measures
Reading 24-hour time. Converting metric units. Adding money with decimals.