My son has no idea that his birthday present was also both a math and science lesson. He has been so interested in plants I gave him a gift certificate to the local garden store.
He felt the plants and tried not to get poked by the cacti.
The desert plants were grouped together, as were the tropical and local plants. Seeing this and selecting some plants to care for he learned a bit more about biomes.
Several times during the visit he rounded the prices of plants to the nearest euro and added them up to estimate how much money he had left. At the end his selection of desert and tropical plants put him over by 18 cents.
Now he is doing a bit more research on caring for his banana tree, zebra plant, and cacti.... and I'm so happy to see him exploring his interests.