Introduce preschoolers to the concepts of "big" and "small" with this charming storybook, "Big and Small on the Farm". Written by Math Brains, this book uses relatable farm animals to help children understand and compare sizes. The story begins on a bright, sunny farm as it's waking up. Throughout the day, readers are introduced to pairs of big and small animals: A big horse and a small pony.A big cow and her small calf.A big pig and a small piglet.A big sheep and her small lamb.A big hen and h