Odd and even numbers

problem

One of Thirty-Six

Age

5 to 7

Challenge level

2 out of 3

Can you find the chosen number from the grid using the clues?
game

Odds and Threes

Age

7 to 11

Challenge level

1 out of 3

A game for 2 people using a pack of cards. Turn over 2 cards and try to make an odd number or a multiple of 3.
game

Down to Nothing

Age

7 to 11

Challenge level

1 out of 3

A game for 2 or more people. Starting with 100, subratct a number from 1 to 9 from the total. You score for making an odd number, a number ending in 0 or a multiple of 6.
problem

Number Tracks

Age

7 to 11

Challenge level

1 out of 3

Ben's class were cutting up number tracks. First they cut them into twos and added up the numbers on each piece. What patterns could they see?
problem

Arrangements

Age

7 to 11

Challenge level

1 out of 3

Is it possible to place 2 counters on the 3 by 3 grid so that there is an even number of counters in every row and every column? How about if you have 3 counters or 4 counters or....?
problem

Three Spinners

Age

7 to 11

Challenge level

1 out of 3

These red, yellow and blue spinners were each spun 45 times in total. Can you work out which numbers are on each spinner?
problem

Diagonal Trace

Age

7 to 11

Challenge level

2 out of 3

You can trace over all of the diagonals of a pentagon without lifting your pencil and without going over any more than once. Can the same thing be done with a hexagon or with a heptagon?
problem

Sets of Numbers

Age

7 to 11

Challenge level

2 out of 3

How many different sets of numbers with at least four members can you find in the numbers in this box?
problem

Sets of Four Numbers

Age

7 to 11

Challenge level

2 out of 3

There are ten children in Becky's group. Can you find a set of numbers for each of them? Are there any other sets?
problem

Crossings

Age

7 to 11

Challenge level

2 out of 3

In this problem we are looking at sets of parallel sticks that cross each other. What is the least number of crossings you can make? And the greatest?