Proof by Exhaustion
Robot Monsters
Use these head, body and leg pieces to make Robot Monsters which are different heights.
6 Beads
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?
School Fair Necklaces
How many possible symmetrical necklaces can you find? How do you know you've found them all?
Reach 100
Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.
Sealed Solution
Ten cards are put into five envelopes so that there are two cards in each envelope. The sum of the numbers inside it is written on each envelope. What numbers could be inside the envelopes?
The Dice Train
This dice train has been made using specific rules. How many different trains can you make?
Factor Lines
Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.