This study notes covers Worked Example 1 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 4 of 7 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.
Worked Example 1
A length is 4.7 m correct to 1 decimal place. Write down the error interval.
Step 1 Find half the accuracy
1 d.p. means accuracy of 0.1 m
Half = 0.05 m
Step 2 Calculate bounds
LB = 4.7 − 0.05 = 4.65
UB = 4.7 + 0.05 = 4.75
Step 3 Write error interval
4.65 ≤ length < 4.75
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 mass m is 45 kg to the nearest kilogram. Write down the error interval for m using inequality notation.