Foundation June 2017 Paper 1 Q15
15.
(a)
Pavel has to work out \(\sqrt{484}\).
Here is his working.
| \(\sqrt{484} = 484 \div 2 = 242\) |
Pavel’s method is incorrect.
Explain why. [1]
(b)
Nina works out \(0{\cdot}54 + 0{\cdot}23 + 2\).
Here is her working.
| \(0{\cdot}54 + 0{\cdot}23 + 2 = \quad \begin{array}{rl} 0{\cdot}54 & \\ 0{\cdot}23 & \\ \underline{\phantom{0{\cdot}5}2} & + \\ 0{\cdot}79 & \end{array}\) |
Nina’s friend says that this answer is too small.
Explain why Nina’s friend is correct. [1]
| Scheme | Marks | Comments |
|---|---|---|
| Valid comment e.g. ‘Incorrect as the answer should be 22’ or ‘Square rooting is not the same as dividing by 2’ or ‘242 squared is not 484’ | B1 | Allow eg ‘Because to find a square root you need to find the number that multiplies by itself.’ |
| Scheme | Marks | Comments |
|---|---|---|
| Valid comment e.g. ‘The answer should be bigger than 2’ or ‘The answer is 2.77’ or ‘She should have added 2.00 not 0.02’ or ‘The 2 has the wrong place value.’ or ‘The two is in the wrong column.’ | B1 | Allow eg ‘2 is a whole number not a decimal.’ |
| (2) |