To make a simple coin sorter, build a box divided by four horizontal boards with holes drilled in them to make five compartments. The holes in the top divider are a bit larger than a quarter; those in the next divider are a bit larger than a nickel; those in the next, a bit larger than a penny; and those in the bottom divider, a bit larger than a dime. Put coins in the top compartment and shake vigorously.
As the coin sorter is shaken, all the coins pass through the first set of holes, since they are all smaller in diameter. When the coins reach the next divider, the quarters do not pass through because the hole is too small, but all the other coin denominations do. This process continues with the other dividers. When all the coins have had a chance to pass through a divider, they are sorted with quarters in the second compartment, nickels in the third, pennies in the fourth and dimes in the bottom.
To make a bank where coins are sorted one at a time as they are inserted, make a box with vertical dividers. Put a sloped, grooved ramp between the dividers and the rear of the box for the coins to roll down. Place a small dowel above the groove horizontally. As the coin rolls down the ramp, the distance between the ramp and the dowel increases. Adjust the ramp as necessary so dimes fall off the ramp into the first compartment, pennies into the second, nickels into the third and quarters into the fourth.