I grew up with this (these) books, my parents bought the set in 1956. I learned to read in the first grade when I was 6 (no one had bothered to give me any guidance till then, my parents weren't readers, I mean they could read it just wasn't their choice of leisure time activities.). It was also in the first grade that I was shown how to "sound out words" (I don't know if children are routinely taught "phonics" today or not).
Once I could sound out words, there was no stopping. I read everything in the house. This set of books, the set of World Book that they purchased at the same time (at least they thought an encyclopedia might come in handy for school). I spent hours following subjects through the encyclopedia... finish an article and it would say "see also" and off I'd go... But this is about a volume of Childcraft. This is the only volume I still have, my brother kept the rest. This one introed me to poetry and it did also to my siblings and my own children. It is liberally annotated in crayon...and full of memories. I hope the others still exist...I loved the stories and games that came from the other volumes.