top of page
This topic writes numbers to a required number of significant figures and truncates (cuts off) rather than rounds, understanding the difference between the two. It's a core topic in GCSE and iGCSE Maths with Edexcel and the other major boards. This free interactive course teaches the method with worked examples and gives instant-feedback practice questions to lock it in.
How you do it
Count significant figures from the first non-zero digit. Zeros in the middle count; leading zeros do not. Truncating means cutting the number off without rounding, so 3.79 truncates to 3.7 but rounds to 3.8.
Before you start
It assumes you can handle rounding and place value. It sets up error intervals and bounds. This is a Foundation and Higher tier topic.
What you learn
Significant figures are the most common way to round in real-world and exam contexts. Truncation is the close cousin that cuts off rather than rounds. The first significant figure is the first non-zero digit, reading from the left. For large numbers, keep the place value by filling with zeros. Truncating means cutting off the extra digits — without rounding. The course works through what significant figures are, significant figures with placeholders and truncation. Every section has instant-feedback practice questions matched to Edexcel iGCSE 4MA1 and the other major GCSE boards, and the course finishes with full exam-style questions you mark yourself.
Related Topics
Significant Figures & Truncation is part of the Number strand of our free GCSE maths courses, studied in Foundation tier. It runs to 3 concepts, each followed by a check, with 2 worked examples along the way. It sits alongside Standard Form, Standard Units & Measures and Surds in the same strand. The Number revision engine gives you as many extra questions as you want, tracked on your skill tree.
Still need help with a topic?
bottom of page