dividing a number of coins in pairs of ratios

this idea is from Martin Wilson in Harrogate
and is intended to be a variation of dividing in a ratio

(sorry about the names, mine rather than Martin's)

unequal sharing

sharing in a ratio
the powerpoint is here
with an additional involvement of looking at what happens when the ratio is changed with the same difference between the two components

mobile moments

the diagrams are sketches, the numbers on the bars show the ratios or proportions along the bars

Dean Ballard's fibonacci mobile

a more recent, colourful version - showing the sub-units














as Dean points out, this version for 13 along the top 'bar' builds from the sub-versions for 8 and 5:

Erich Friedman's weight puzzles are thought provoking tasks:
there are puzzles for 5 consecutive numbers right up to 20 consecutive numbers

place weights 1 to 5 so that this mobile balances

place weights 1 to 5 so that this mobile balances

place weights 1 to 6 so that this balances

place weights 1 to 7 so that this balances