Working systematically

problem

Leap Frog

Age

5 to 7

Challenge level

The brown frog and green frog want to swap places without getting wet. They can hop onto a lily pad next to them, or hop over each other. How could they do it?
problem
Favourite

6 Beads

Age

5 to 7

Challenge level

If you put three beads onto a tens/ones abacus you can make the numbers 3, 30, 12 or 21. What numbers can be made with six beads?
problem

Snakes

Age

5 to 7

Challenge level

Explore the different snakes that can be made using 5 cubes.
problem
Favourite

Mixed-Up Socks

Age

5 to 7

Challenge level

Start with three pairs of socks. Now mix them up so that no mismatched pair is the same as another mismatched pair. Is there more than one way to do it?
problem

Jumping Cricket

Age

5 to 7

Challenge level

El Crico the cricket has to cross a square patio to get home. He can jump the length of one tile, two tiles and three tiles. Can you find a path that would get El Crico home in three jumps?
problem

Teddy Bear Line-Up

Age

5 to 7

Challenge level

What is the least number of moves you can take to rearrange the bears so that no bear is next to a bear of the same colour?
problem
Favourite

Birthday Cakes

Age

5 to 7

Challenge level

Jack's mum bought some candles to use on his birthday cakes and when his sister was born, she used them on her cakes too. Can you use the information to find out when Kate was born?
problem
Favourite

Heads and Feet

Age

5 to 7

Challenge level

On a farm there were some hens and sheep. Altogether there were 8 heads and 22 feet. How many hens were there?
problem

Briefcase Lock

Age

5 to 7

Challenge level

My briefcase has a three-number combination lock, but I have forgotten the combination. I remember that there's a 3, a 5 and an 8. How many possible combinations are there to try?
problem

Whose Sandwich?

Age

5 to 7

Challenge level

Chandra, Jane, Terry and Harry ordered their lunches from the sandwich shop. Use the information below to find out who ordered each sandwich.