Creating and manipulating expressions and formulae
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problemFavouriteFinding 3D Stacks
Can you find a way of counting the spheres in these arrangements?
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problemFavouriteYour Number Is...
Think of a number and follow the machine's instructions... I know what your number is! Can you explain how I know?
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problemFavouriteThe Number Jumbler
The Number Jumbler can always work out your chosen symbol. Can you work out how?
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problemFavouriteDiagonal Sums
In this 100 square, look at the green square which contains the numbers 2, 3, 12 and 13. What is the sum of the numbers that are diagonally opposite each other? What do you notice?
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problemFavouriteMind Reading
Think of a number, add one, double it, take away 3, add the number you first thought of, add 7, divide by 3 and take away the number you first thought of. You should now be left with 2. How do I know?
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problemFavouriteSpecial Numbers
My two digit number is special because adding the sum of its digits to the product of its digits gives me my original number. What could my number be?
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problemFavouritePartitioning Revisited
We can show that (x + 1)² = x² + 2x + 1 by considering the area of an (x + 1) by (x + 1) square. Show in a similar way that (x + 2)² = x² + 4x + 4
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problemFavouriteCrossed Ends
Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?
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problemFavouriteHow Much Can We Spend?
A country has decided to have just two different coins. Which totals can be made? Is there a largest total that cannot be made? How do you know?