Cardboard Gravity Coin Sorter

Cut a long strip of cardboard to form a sloped ramp for the coins to slide down.

Measure and cut precise slots along the ramp starting from the smallest coin diameter to the largest.

Glue low cardboard guide rails along the edges of the ramp to keep rolling coins in line.

Build small cardboard collection trays directly beneath each cut out slot.

Prop the ramp up at a gentle slope inside a cardboard shoe box base.

Drop a mixed handful of coins at the top of the ramp to watch them sort themselves into the matching slots.