Working backwards from a rounded number
Working backwards from a rounded value to find the smallest and largest numbers it could have been.
The Question
A whole number rounds to 4,700 when rounded to the nearest hundred. What is the smallest it could be, and what is the largest?
The Answer
Reveal the Answer
The boundary at 4,650 rounds up and is included; 4,750 would round to 4,800, so the largest whole number is 4,749. Draw the number line and shade the interval — the asymmetry at the two ends is the point.
Now watch the solution
Practice Sheet + Marked Answers
The four-question practice sheet, the solutions in our teaching voice and a self-marking quiz for this question are part of The Question Desk course — every school day of the term, with progress you can see. Enrolled group students get it included.
Want a Plan Built Around Your Child, Not Just This Week’s Question?
Small groups of around 4–5 (max 8), matched to your child’s year group and pace. Start with the free baseline assessment and we’ll tell you exactly where they are.
