4400 Higher June 2007 Paper 4 Q4
4 Julian has to work out \(\dfrac{6.8 \times 47.6}{2.09}\) without using a calculator.
(a) Round each number in Julian’s calculation to one significant figure. (2)
(b) Use your rounded numbers to work out an estimate for \(\dfrac{6.8 \times 47.6}{2.09}\)
Give your answer correct to one significant figure. (2)
Give your answer correct to one significant figure. (2)
(c) Without using your calculator, explain why your answer to part (b) should be larger than the exact answer. (2)
| Scheme | Marks |
|---|---|
| \(\dfrac{7 \times 50}{2}\) or 7, 50, 2 | B1 |
| B1 | |
| (2) |
Notes
B1: for 7 and 2
B1: for 50
| Scheme | Marks |
|---|---|
| 175 | M1 |
| 200 or 100 | A1ft |
| (2) |
Notes
M1: \(\dfrac{(6 \text{ or } 7) \times (48 \text{ or } 50)}{2 \text{ or } 3}\) correctly eval’d eg 168
A1ft: If no wking: ft (a)
| Scheme | Marks |
|---|---|
| Num incr or 6.8 & 47.6 incr denom decr or 2.09 decr (b) rnded up (not rnd to 1 sf) or ‘175’ rnded to 200 | B2 |
| (2) | |
| (6 marks) |
Notes
B2: any two of these
B1 any one of these. Ignore other