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