Maths Quiz - Addition and Subtraction 3 (Medium) (Answers)
So, you have made it to the third quiz in our Medium section of Eleven Plus maths quizzes on Addition and Subtraction. If you have already played all our previous quizzes on the topic, then well done you! If you haven’t then you may wish to go back and play them before you tackle this quiz.
Solving addition and subtraction problems is one of the easiest parts of maths. But what if the questions involve 3-figure numbers in the hundreds? You will be pleased to hear that they are no different to any other addition or subtraction problems – they just have an extra column.
TIP: With 3-figure numbers, add the hundreds first, then the tens and then the ones.
Sometimes you will spot some shortcuts which mean you don’t have to do the calculations the long way round. You’ll find more tips in the helpful comments to this quiz. So, if you are ready, let’s play!
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A quick way to add 690 is to add 700 then subtract 10.
Here’s the other way to solve the problem, by adding the hundreds first, then the tens and then the ones: 690 + 426 - 888 = (600 + 400 - 800) + (90 + 20 - 80) + (0 + 6 - 8) = 200 + 30 + -2 = 228 |
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600 + 400 = 1,000. Keep your eyes peeled, looking for ways to break the problem up into smaller sums
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Remember, 100s first, then 10s, then ones:
894 - 183 - 500 + 17 = (800 - 500 - 100) + (90 + 10 - 80 - 0) + (4 + 7 - 3 - 0) = 200 + 20 + 8 = 228 |
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To avoid working with negative numbers, you can rearrange the problem:
53 - 467 + 643 = (53 + 643) - 467 = 696 - 467 = 229 |
In multiple choice questions, the last digit in the answers can help you find the correct answer more quickly. 0 + 3 - 3 = 0 so you know the correct answer will end with a zero. Be on the LOOKOUT FOR SHORT CUTS like this
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Always look out for shortcuts: the 400s in 420 – 403 cancel each other out, making the answer the same as 20 - 3
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Remember: in multiple choice quizzes, the last digit in a number can show you the right answer. 1 + 6 - 5 = 2, so the last digit in the correct answer will also be a 2
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It's a good idea to add the hundreds first, then the tens and finally the ones:
353 - 28 + 11 + 27 = (300) + (50 + 10 + 20 - 20) + (3 + 1 + 7 - 8) = 300 + 60 + 3 = 363 |
TIP: With numbers less than 1,000, add the hundreds first, then the tens and then the ones.
909 + 76 - 654 - 13 = (900 - 600) + (0 + 70 - 50 - 10) + (9 + 6 - 4 - 3) = 300 + 10 + 8 = 318 You can repeat the procedure if you are having difficulty in doing it in your head |
926 + 220 - 403 = (900 + 200 - 400) + (20 + 20 - 0) + (6 + 0 - 3) = (700) + (40) + (3) = 743
You can ignore the zeros