Vintage 60s childrens books / wheels / big and small / martha and charles shapp

Set of two vintage children's books by Martha and Charles Shapp. Hardcovered books with moderate exterior wear and tear, but still very cute books! Will contain: 1) "Let's Find Out About Wheels" by Martha and Charles Shapp with illustrations by Peter Costanza. Published in 1962. This book has some brown stains on the inside of the back cover and a stamp from the Board of Education, City of New York. This book basically teaches that wheels are everywhere and that they make our lives easier! Before the wheel was discovered, life was much harder! 2) "Let's Find Out What's Big and What's Small" by Martha and Charles Shapp with illustrations by Vana Earle. Published in 1959. As shown in the photos, the back of the book has green marker across the back. There is also green crayon inside the front cover and a stamp from the Board of Education, City of New York. The first couple pages have a bent in the corner of the pages and the last page (vocabulary list) has some green marking at the bottom. This book is really cute because it teaches that big and small are both relative and perspective can change whether something is big or small!