Children encounter lots of word and math based learning at school. Exposing kids to too many will probably deplete their enthusiasm for learning. Sometimes kids at this age need a break from being bombarded by the alphabet etc.
If you want to give your child the best learning toys for this age, think about choosing toys that encourage other avenues of thinking rather than basic school stuff alone. Although these toys are tempting from the parent's perspective, instead think about how to nurture their other skills. You can improve both their physical and mental skills with these toys.