Nature Math, Level 4

Large numbers stop being intuitive somewhere around a thousand, and this level is about rebuilding intuition past that point.

The approach is physical for as long as physical is possible. You can lay out a hundred seeds. You cannot lay out ten thousand, and the moment a child hits that wall is the moment the notation starts doing real work for them. The guide walks into that wall on purpose rather than around it.

Sixteen pages covering reading, writing, building, comparing and rounding, with the same four section structure as every other level.

Grade four is also where children start needing to check their own answers, so several pages include a way to test whether the result is sensible. Estimating first and calculating second is a habit worth building here and hard to install later.