Create your own centimeter ruler. Then, estimate and measure with lengths with it. Warm up with a Mystery Math Mistake as you add two 2-digit numbers using a decomposition strategy. Think through ...

Preschool children who showed less ability to estimate the number of objects in a group were 2.4 times more likely to have a later mathematical learning disability than other young people, according ...

“It’s about being able to step back and look at your result. Does it make sense?” says Stefan Funk, a particle physicist who ...