Estimation

Rapidly approximate complex equations using the power of rounding.

What you'll learn

Core 11+ exam skills

Rounding to 1 SF

Develop foundational techniques logically.

Estimating Addition

Apply mathematical rules to varying scenarios.

Estimating Multiplication

Learn to track calculations dynamically.

Checking Answers

Verify accuracy and solve efficiently.

The mechanics of Estimation

Significant Figures

Round everything to 1 significant figure first.

Mental Maths

Use approximations (e.g., 99 × 4 ≈ 100 × 4).

Reasonableness

If you buy 3 apples, it won't cost £4000.

Upper/Lower Bounds

Recognizing if your guess is too high or too low.

💡

Estimation is your best defense against silly calculator errors.

🔄

The symbol "≈" means "is approximately equal to".

➕

Round BEFORE you calculate, not after.

➖

If you round numbers up, your estimate will be higher than the true answer.

Choose your mode