Turner needs $328 to purchase flexible seats and Unifix cubes for her classroom. Once she is fully funded, DonorsChoose will buy the items and deliver them to the school.

The Didax Educational Resources Unifix Cubes Set ($12, originally $14) comes with 100 interlocking counting cubes and an activity booklet to help hone math skills.

At one station, a little boy named David is holding a stick up to a lightbulb to form shadows, and using Unifix Cubes to measure the shadow’s length at different angles. He holds the lamp close to the ...