Addition and subtraction

problem

Worms

Age

7 to 11

Challenge level

2 out of 3

Place this "worm" on the 100 square and find the total of the four squares it covers. Keeping its head in the same place, what other totals can you make?
problem

Dice and Spinner Numbers

Age

7 to 11

Challenge level

2 out of 3

If you had any number of ordinary dice, what are the possible ways of making their totals 6? What would the product of the dice be each time?
problem

Bean Bags for Bernard's Bag

Age

7 to 11

Challenge level

2 out of 3

How could you put eight bean bags in the hoops so that there are four in the blue hoop, five in the red and six in the yellow? Can you find all the ways of doing this?
problem

Magic Constants

Age

7 to 11

Challenge level

2 out of 3

In a Magic Square all the rows, columns and diagonals add to the 'Magic Constant'. How would you change the magic constant of this square?
problem

X Is 5 Squares

Age

7 to 11

Challenge level

2 out of 3

Can you arrange 5 different digits (from 0 - 9) in the cross in the way described?
problem

How Old?

Age

7 to 11

Challenge level

2 out of 3

Cherri, Saxon, Mel and Paul are friends. They are all different ages. Can you find out the age of each friend using the information?
problem

Hubble, Bubble

Age

7 to 11

Challenge level

2 out of 3

Winifred Wytsh bought a box each of jelly babies, milk jelly bears, yellow jelly bees and jelly belly beans. In how many different ways could she make a jolly jelly feast with 32 legs?
problem

Six Is the Sum

Age

7 to 11

Challenge level

2 out of 3

What do the digits in the number fifteen add up to? How many other numbers have digits with the same total but no zeros?
problem

Two Egg Timers

Age

7 to 11

Challenge level

2 out of 3

You have two egg timers. One takes 4 minutes exactly to empty and the other takes 7 minutes. What times in whole minutes can you measure and how?
problem

Book Codes

Age

7 to 11

Challenge level

2 out of 3

Look on the back of any modern book and you will find an ISBN code. Take this code and calculate this sum in the way shown. Can you see what the answers always have in common?