Working backwards can be a very useful problem-solving skill. These activities lend themselves to being tackled in this way.
This collection is one of our Primary Curriculum collections - tasks that are grouped by topic.
problem
Favourite
Nim-7
Age
5 to 11
Challenge level
Can you work out how to win this game of Nim? Does it matter if you go first or second?
problem
Junior Frogs
Age
5 to 11
Challenge level
Have a go at this well-known challenge. Can you swap the frogs and toads in as few slides and jumps as possible?
problem
Favourite
What's in the Box?
Age
7 to 11
Challenge level
This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?
problem
Favourite
First Connect Three
Age
7 to 11
Challenge level
Add or subtract the two numbers on the spinners and try to complete a row of three. Are there some numbers that are good to aim for?
problem
Favourite
Nice or Nasty
Age
7 to 14
Challenge level
There are nasty versions of this dice game but we'll start with the nice ones...
problem
Favourite
Missing Multipliers
Age
7 to 14
Challenge level
What is the smallest number of answers you need to reveal in order to work out the missing headers?
problem
Favourite
Play to 37
Age
7 to 11
Challenge level
In this game for two players, the idea is to take it in turns to choose 1, 3, 5 or 7. The winner is the first to make the total 37.
problem
Favourite
Would You Rather?
Age
7 to 11
Challenge level
Would you rather: Have 10% of £5 or 75% of 80p? Be given 60% of 2 pizzas or 26% of 5 pizzas?
problem
Favourite
Multiplication Squares
Age
7 to 11
Challenge level
Can you work out the arrangement of the digits in the square so that the given products are correct? The numbers 1 - 9 may be used once and once only.
problem
Favourite
Maze 100
Age
7 to 11
Challenge level
Can you go through this maze so that the numbers you pass add to exactly 100?
problem
Favourite
Mystery Matrix
Age
7 to 11
Challenge level
Can you fill in this table square? The numbers 2 -12 were used to generate it with just one number used twice.
problem
Favourite
All the Digits
Age
7 to 11
Challenge level
This multiplication uses each of the digits 0 - 9 once and once only. Using the information given, can you replace the stars in the calculation with figures?
problem
Favourite
Got It
Age
7 to 14
Challenge level
A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.
problem
Favourite
Andy's Marbles
Age
7 to 11
Challenge level
Andy had a big bag of marbles but unfortunately the bottom of it split and all the marbles spilled out. Use the information to find out how many there were in the bag originally.
problem
Favourite
Counting Cards
Age
7 to 11
Challenge level
A magician took a suit of thirteen cards and held them in his hand
face down. Every card he revealed had the same value as the one he
had just finished spelling. How did this work?