For a fun and hands on approach to teaching estimation, check out the blog Teach Preschool. These cute little jars are one of our favorite featured ideas. Use them to teach about numbers, to encourage language (“more”, “less”, “dozens”, “hundreds”), and to encourage exploration. Little ones with fine motor problems will find the jars easier to manipulate than smaller loose manipulatives. Want to really up the excitement? Try adding objects that students find irresistible. Have a student who loves things that move? Fill a jar with toy wheels or little cars. Know a child who loves Barbie? Create a jar filled with her shoes!