IGCSE Maths / Fractions, decimals and rounding

Estimating by rounding revision notes

Edexcel International GCSE Maths (4MA1), chapter 1: Fractions, decimals and rounding, specification point 1.8d-f. Part of the full course.

Watch the video lesson · IGCSE Maths past papers

To estimate a calculation, round every number to one significant figure first, then calculate using the rounded values. Estimates give a quick sense check and the working earns marks.

More lessons in Fractions, decimals and rounding

• Directed numbers
• Equivalent fractions and simplifying
• Mixed numbers and improper fractions
• Adding and subtracting fractions
• A fraction of a quantity
• Multiplying and dividing fractions
• Ordering decimals
• Fractions, decimals and percentages
• Recurring decimals to fractions
• Mixed recurring decimals
• Rounding to decimal places and significant figures
• Finding upper and lower bounds
• Calculating with bounds