627 + 183 = ?
20 – 3 × 5 = ?
Put these numbers in order of magnitude from smallest to biggest:
0.5 0.03 1 0.1 1.5 0.3 0.55 0.05
0.001 is equal to which of the following?
1 1
1
(a) –––
(b) –––– (c) –––––
10 100 1000
¾ + 0.6 = ?
If y = x – 2, what is the value of x when y = 6?
Write 3.75 million in figures.
√(3^{2} + 4^{2}) = ?
What is 2½% of £10?
If cheese is £4.40 per kilogramme, what should I pay for 200 grammes?
The answers are:
627 + 183 = 810
20 – 3 × 5 = 5.
Note that the order of operations in maths is
brackets, powers of, divide, multiply, add, subtract.
Put these numbers in order of magnitude from smallest to biggest:
0.5 0.03 1 0.1 1.5 0.3 0.55 0.05
gives us
0.03 0.05 0.1 0.3 0.5 0.55 1 1.5
0.001 is equal to which of the following?
1 1
1
(a) –––
(b) –––– (c) –––––
10 100 1000
The answer is c.
¾ + 0.6 = 0.75 + 0.6 = 1.35.
I would also accept 1 7/20 or 27/20.
If y = x – 2, the value of x when y = 6 is 8.
Write 3.75 million in figures: 3,750,000.
√(3^{2} + 4^{2}) = √(9 + 16) = √25 = 5.
2½% of £10 = £0.25 = 25p.
If cheese is £4.40 per kilogramme, for 200 grammes I should pay £4.40 × 200/1000 = £0.88 = 88p.
There were 37 students. The numbers getting each possible score out of 10 were:
Score | Count | % |
---|---|---|
0 | 0 | 0.0 |
1 | 0 | 0.0 |
2 | 0 | 0.0 |
3 | 0 | 0.0 |
4 | 2 | 5.4 |
5 | 4 | 10.8 |
6 | 1 | 2.7 |
7 | 4 | 10.8 |
8 | 5 | 13.5 |
9 | 8 | 21.6 |
10 | 13 | 35.1 |
We can present this graphically:
Hence 11 students got 7 or less, the score that I suggested meant that they should brush up their maths.
The question which caused most trouble was 2: 20 – 3 × 5 = ?. 48% got this wrong, all giving the answer 85. They got this by first subtracting 3 from 20 then multiplying 17 by 5. The rules of arithmetic are that we multiply before we add. We do not need brackets to make this clear. See part 1 of Brush up your maths.
We asked whether you panicked when you saw all those numbers. 19 said 'yes' to this. Not surprisingly, the panickers did worst, with mean score = 7.0, compared to 9.3 for those who did not panic.
These results were better than in previous years, well done.
Martin Bland
October, 2010.
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Last updated: 18 October, 2010.