Foundation June 2018 Paper 3 Q15
15 Jenny is asked to find the value of \(12 - 2 \times 4\)
Here is her working.
\(12 - 2 \times 4 = 10 \times 4 = 40\)
Jenny’s answer is wrong.
(a) Explain what Jenny has done wrong. (1)
Rehan is asked to find the range of the numbers 3 1 8 7 5
Here is his working.
Range = \(5 - 3 = 2\)
This is wrong.
(b) Explain why. (1)
| Answer | Mark | Mark scheme |
|---|---|---|
| Incorrect order of operation | C1 | for identifying an incorrect order of operation, eg should be \(12 - 8\) or “should multiply first” |
Additional guidance
Showing that \(12 - 2 \times 4\) is 4 (and not 40) is insufficient for this mark; the explanation should focus on what Jenny has done wrong.
| Answer | Mark | Mark scheme |
|---|---|---|
| Statement | C1 | for stating that the range is the difference between the greatest and least values, oe or stating that he didn’t put numbers in order |
Additional guidance
Stating the correct calculation for the range \((8 - 1)\) or stating the (correct) range as 7 is sufficient for this mark.