List

Year 11+ Reasoning, convincing and proving

Shopping Basket
problem

Shopping basket

Age
11 to 16
Challenge level
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The items in the shopping basket add and multiply to give the same amount. What could their prices be?

Summing geometric progressions
problem

Summing geometric progressions

Age
14 to 18
Challenge level
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Watch the video to see how to sum the sequence. Can you adapt the method to sum other sequences?

Mega Quadratic Equations
problem

Mega quadratic equations

Age
14 to 18
Challenge level
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What do you get when you raise a quadratic to the power of a quadratic?
Trapezium Four
problem

Trapezium four

Age
14 to 16
Challenge level
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The diagonals of a trapezium divide it into four parts. Can you create a trapezium where three of those parts are equal in area?

Curve fitter
problem

Curve fitter

Age
14 to 18
Challenge level
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This problem challenges you to find cubic equations which satisfy different conditions.

Back fitter
problem

Back fitter

Age
14 to 18
Challenge level
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10 graphs of experimental data are given. Can you use a spreadsheet to find algebraic graphs which match them closely, and thus discover the formulae most likely to govern the underlying processes?

Fill Me Up Too
problem

Fill me up too

Age
14 to 16
Challenge level
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In Fill Me Up we invited you to sketch graphs as vessels are filled with water. Can you work out the equations of the graphs?

Sitting Pretty
problem

Sitting pretty

Age
14 to 16
Challenge level
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A circle of radius r touches two sides of a right angled triangle, sides x and y, and has its centre on the hypotenuse. Can you prove the formula linking x, y and r?

Why 24?
problem

Why 24?

Age
14 to 16
Challenge level
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Take any prime number greater than 3 , square it and subtract one. Working on the building blocks will help you to explain what is special about your results.
Iff
problem

Iff

Age
14 to 18
Challenge level
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Take a triangular number, multiply it by 8 and add 1. What is special about your answer? Can you prove it?
Always Perfect
problem

Always perfect

Age
14 to 18
Challenge level
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Show that if you add 1 to the product of four consecutive numbers the answer is ALWAYS a perfect square.
Squirty
problem

Squirty

Age
14 to 16
Challenge level
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Using a ruler, pencil and compasses only, it is possible to construct a square inside any triangle so that all four vertices touch the sides of the triangle.

Difference Sudoku
problem

Difference Sudoku

Age
14 to 16
Challenge level
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Use the differences to find the solution to this Sudoku.

Partly Circles
problem

Partly circles

Age
14 to 16
Challenge level
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What is the same and what is different about these circle questions? What connections can you make?

2-Digit Square
problem

2-digit square

Age
14 to 16
Challenge level
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A 2-Digit number is squared. When this 2-digit number is reversed and squared, the difference between the squares is also a square. What is the 2-digit number?
Angle Trisection
problem

Angle trisection

Age
14 to 16
Challenge level
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It is impossible to trisect an angle using only ruler and compasses but it can be done using a carpenter's square.