Fractions

problem
Twisting and turning

Age

11 to 14

Challenge level

Take a look at the video and try to find a sequence of moves that will untangle the ropes.
problem
Information display

Age

11 to 14

Challenge level

The information display on a train shows letters by illuminating dots in a rectangular array. What fraction of the dots in this array is illuminated?
problem
Recurring mean

Age

14 to 16

Challenge level

What is the mean of 1.2 recurring and 2.1 recurring?
problem
Percentage swap

Age

14 to 16

Challenge level

What is 50% of 2007 plus 2007% of 50?
problem
A chance to win?

Age

11 to 14

Challenge level

Imagine you were given the chance to win some money... and imagine you had nothing to lose...
problem
Ratio Sudoku 3

Age

11 to 16

Challenge level

A Sudoku with clues as ratios or fractions.
problem
Making longer, making shorter

Age

5 to 7

Challenge level

Ahmed is making rods using different numbers of cubes. Which rod is twice the length of his first rod?
problem
Magic matrix

Age

7 to 11

Challenge level

Find out why these matrices are magic. Can you work out how they were made? Can you make your own Magic Matrix?
problem
Equal temperament

Age

14 to 16

Challenge level

The scale on a piano does something clever : the ratio (interval) between any adjacent points on the scale is equal. If you play any note, twelve points higher will be exactly an octave on.
problem
Pythagoras' comma

Age

14 to 16

Challenge level

Using an understanding that 1:2 and 2:3 were good ratios, start with a length and keep reducing it to 2/3 of itself. Each time that took the length under 1/2 they doubled it to get back within range.