NP Worksheets Help
Pyramids
With „Pyramids“ you can practice addition [ + ] and subtraction [ – ] operations in the range from 0 to 1000.
A „Pyramid“ is built out of bricks. There are numbers painted on those bricks. Each brick's number is the sum of the two numbers under it (see images below).
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4 + 3 = 7 |
3 + 7 = 10 |
7 + 10 = 17 |
Solving pyramids (Mode 4)
In the picture above we wrote letters instead of numbers into the bricks. As you can see, the top brick is always the result of the sum of a, c and double of b.
If we have a pyramid, where only a, c and the top brick are known, then we can calculate b as follows:
- Subtract a and c from the top brick.
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Divide the result by two to get b.
A real example:
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Subtract a and c from the top brick:
20 – 6 – 4 = 10
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Divide the result by two to get b:
10 : 2 = 5
So: b = 5
- Now the pyramid can be solved as usual.