NumberDeep Dive

Bounds in Calculations (Key for Exam!)

Part of Bounds & Error IntervalsGCSE Mathematics

This deep dive covers Bounds in Calculations (Key for Exam!) within Bounds & Error Intervals for GCSE Mathematics. Revise Bounds & Error Intervals in Number for GCSE Mathematics with 14 exam-style questions and 5 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 5 of 6 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 5 of 6

Practice

14 questions

Recall

5 flashcards

Bounds in Calculations (Key for Exam!)

To find... Use...
Maximum of A + B UB(A) + UB(B)
Minimum of A + B LB(A) + LB(B)
Maximum of A − B UB(A) − LB(B)
Minimum of A − B LB(A) − UB(B)
Maximum of A × B UB(A) × UB(B)
Minimum of A × B LB(A) × LB(B)
Maximum of A ÷ B UB(A) ÷ LB(B)
Minimum of A ÷ B LB(A) ÷ UB(B)

Memory trick: For division, it's the OPPOSITE - to make a fraction big, make the top big and bottom small!

Keep building this topic

Read this section alongside the surrounding pages in Bounds & Error Intervals. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Bounds & Error Intervals

A length is 240 cm to the nearest 10 cm. What is the lower bound of the length?

  • A. 230 cm
  • B. 235 cm
  • C. 239 cm
  • D. 245 cm
1 markfoundation

A mass m is 45 kg to the nearest kilogram. Write down the error interval for m using inequality notation.

2 marksfoundation

Quick Recall Flashcards

Max of A ÷ B
Max = UB(A) ÷ LB(B). Big top, small bottom = big answer
Rationalising
Remove surd from denominator: 1/√2 = √2/2

Want to test your knowledge?

PrepWise has 14 exam-style questions and 5 flashcards for Bounds & Error Intervals — with adaptive difficulty and instant feedback.

Join Alpha