I think most kids can do this. All 3 of my kids have been able to read, write a sentence (with very bad handwriting), and understand the concept of repeated add

I think most kids can do this. All 3 of my kids have been able to read, write a sentence (with very bad handwriting), and understand the concept of repeated addition and multiply slowly before age 4. It's also only very poorly correlated with better academic outcomes overall.