These medium sets of wooden blocks will work for kids from age 4-5 up. The Beginner Set A is our most popular set in terms of numbers. It is a detailed set, but it is easy to add large blocks to add by buying our Beginner Set C which combines the Beginner Set A and an additional carton of just large blocks. This set is just short of the base set A found in the Standard Sets in the ext category. A number of other of the Beginner Sets are designed for special audiences and you should explore these all before making a decision. It's always possible to augment a sert using Open Stock or Booster Sets. It's mostly a matter of budget. Buy what you can afford and add more of our maple blocks later or ansert that auntie who calls and asks what to by for Christmas or Hanukah. All of our unit blocks adhere to the standard for school size blocks and the individual blocks remain the same as the sets get bigger. If you buy a smaller set you are completely free to add blocks to it later as your child's needs expand. Our Open Stock pages will allow you to add individual blocks and our Booster Sets will allow you to add a bunch of wooden building blocks to expand an existing set.