Representation - October 2008, All Stages

Problems

problem icon

Magic Plant

Stage: 1 Challenge Level: Challenge Level:2 Challenge Level:2

On Friday the magic plant was only 2 centimetres tall. Every day it doubled its height. How tall was it on Monday?

problem icon

Find the Difference

Stage: 1 Challenge Level: Challenge Level:2 Challenge Level:2

Place the numbers 1 to 6 in the circles so that each number is the difference between the two numbers just below it.

problem icon

Biscuit Decorations

Stage: 1 and 2 Challenge Level: Challenge Level:1

Andrew decorated 20 biscuits to take to a party. He lined them up and put icing on every second biscuit and different decorations on other biscuits. How many biscuits weren't decorated?

problem icon

Ladybird Box

Stage: 1 and 2 Challenge Level: Challenge Level:2 Challenge Level:2

Place six toy ladybirds into the box so that there are two ladybirds in every column and every row.

problem icon

Three Squares

Stage: 1 and 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

What is the greatest number of squares you can make by overlapping three squares?

problem icon

Five Coins

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Ben has five coins in his pocket. How much money might he have?

problem icon

Quadrilaterals

Stage: 2 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

How many DIFFERENT quadrilaterals can be made by joining the dots on the 8-point circle?

problem icon

Crossed Ends

Stage: 3 Challenge Level: Challenge Level:1

Crosses can be drawn on number grids of various sizes. What do you notice when you add opposite ends?

problem icon

Legs Eleven

Stage: 3 Challenge Level: Challenge Level:2 Challenge Level:2

Take any four digit number. Move the first digit to the end and move the rest along. Now add your two numbers. Did you get a multiple of 11?

problem icon

Domino Square

Stage: 2, 3 and 4 Challenge Level: Challenge Level:2 Challenge Level:2

Use the 'double-3 down' dominoes to make a square so that each side has eight dots.

problem icon

Differences

Stage: 3 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Can you guarantee that, for any three numbers you choose, the product of their differences will always be an even number?

problem icon

Tet-trouble

Stage: 4 Challenge Level: Challenge Level:2 Challenge Level:2

Show that is it impossible to have a tetrahedron whose six edges have lengths 10, 20, 30, 40, 50 and 60 units...

problem icon

Hexy-metry

Stage: 4 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

A hexagon, with sides alternately a and b units in length, is inscribed in a circle. How big is the radius of the circle?

problem icon

Napoleon's Theorem

Stage: 4 and 5 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Triangle ABC has equilateral triangles drawn on its edges. Points P, Q and R are the centres of the equilateral triangles. What can you prove about the triangle PQR?

problem icon

Sixty-seven Squared

Stage: 5 Challenge Level: Challenge Level:1

Evaluate these powers of 67. What do you notice? Can you convince someone what the answer would be to (a million sixes followed by a 7) squared?

problem icon

Chord

Stage: 5 Challenge Level: Challenge Level:1

Equal touching circles have centres on a line. From a point of this line on a circle, a tangent is drawn to the farthest circle. Find the lengths of chords where the line cuts the other circles.

problem icon

Pythagoras for a Tetrahedron

Stage: 5 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

In a right-angled tetrahedron prove that the sum of the squares of the areas of the 3 faces in mutually perpendicular planes equals the square of the area of the sloping face. A generalisation. . . .