Working Systematically - Lower Secondary

Two and Two

KS 2 & 3 Challenge Level:

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

How many solutions can you find to this sum? Each of the different letters stands for a different number.

Summing Consecutive Numbers

KS 3 Challenge Level:

Challenge Level:1

Many numbers can be expressed as the sum of two or more consecutive integers. For example, 15=7+8 and 10=1+2+3+4. Can you say which numbers can be expressed in this way?

Isosceles Triangles

KS 3 Challenge Level:

Challenge Level:1

Draw some isosceles triangles with an area of $9$cm$^2$ and a vertex at (20,20). If all the vertices must have whole number coordinates, how many is it possible to draw?

Nine Colours

KS 3 Challenge Level:

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

You have 27 small cubes, 3 each of nine colours. Use the small cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of every colour.

ACE, TWO, THREE...

KS 3 Challenge Level:

Challenge Level:1

Can you picture how to order the cards to reproduce Charlie's card trick for yourself?

American Billions

KS 3 Challenge Level:

Challenge Level:1

Play the divisibility game to create numbers in which the first two digits make a number divisible by 2, the first three digits make a number divisible by 3...

M, M and M

KS 3 Challenge Level:

Challenge Level:1

If you are given the mean, median and mode of five positive whole numbers, can you find the numbers?

1 Step 2 Step

KS 3 Challenge Level:

Challenge Level:1

Liam's house has a staircase with 12 steps. He can go down the steps one at a time or two at time. In how many different ways can Liam go down the 12 steps?

Can They Be Equal?

KS 3 Challenge Level:

Challenge Level:1

Can you find rectangles where the value of the area is the same as the value of the perimeter?

Pick's Theorem

KS 3 Challenge Level:

Challenge Level:1

Polygons drawn on square dotty paper have dots on their perimeter (p) and often internal (i) ones as well. Find a relationship between p, i and the area of the polygons.

Sticky Numbers

KS 3 Challenge Level:

Challenge Level:1

Can you arrange the numbers 1 to 17 in a row so that each adjacent pair adds up to a square number?

Shady Symmetry

KS 3 Challenge Level:

Challenge Level:1

How many different symmetrical shapes can you make by shading triangles or squares?

Shifting Times Tables

KS 3 Challenge Level:

Challenge Level:1

Can you find a way to identify times tables after they have been shifted up?

Peaches Today, Peaches Tomorrow....

KS 3 & 4 Challenge Level:

Challenge Level:2 Challenge Level:2

Whenever a monkey has peaches, he always keeps a fraction of them each day, gives the rest away, and then eats one. How long could he make his peaches last for?

Charlie's Delightful Machine

KS 3 & 4 Challenge Level:

Challenge Level:1

Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?

What's Possible?

KS 4 Challenge Level:

Challenge Level:2 Challenge Level:2

Many numbers can be expressed as the difference of two perfect squares. What do you notice about the numbers you CANNOT make?

A Long Time at the Till

KS 4 & 5 Challenge Level:

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

Try to solve this very difficult problem and then study our two suggested solutions. How would you use your knowledge to try to solve variants on the original problem?