Little kids love storytime, and reading to children doesn’t just entertain them, it is a vital form of early childhood education.

A recent study published in the Journal of Developmental and Behavioral Pediatrics found that kids whose parents read them five books a day start kindergarten having heard more than a million more words than children whose parents don’t read to them.

And if five books per day isn’t always doable for you, don’t worry—the researchers found even one book per day gives kids a boost of about 290,000 more words by age five. “Kids who hear more vocabulary words are going to be better prepared to see those words in print when they enter school,” says Jessica Logan, lead author of the study and assistant professor of educational studies at The Ohio State University.

Logan says she dove into this research because she was pretty shocked by what she heard during one of her previous studies, which found a quarter of kids are never read to. “The fact that we had so many parents who said they never or seldom read to their kids was pretty shocking to us. We wanted to figure out what that might mean for their kids,” she explains in a media release.

Logan and her colleagues did the math using the 100 most read board books and picture books checked out from the Columbus Metropolitan Library,

Based on these calculations, here’s how many words they estimate kids hear by the time they are 5 years old:

If they’re never read to, they’ll have heard 4,662 words.

If they’re read to 1-2 times per week, they’ll have heard 63,570 words.

If they’re read to 3-5 times per week, they’ll have heard 169,520 words.

If they’re read to daily, they’ll have heard 296,660 words.

And if they’re read five books a day, they’ll have heard a whopping 1,483,300 words by age five.

For Logan, the gap here is striking, and she notes that there’s a difference between the kind of vocabulary our kids hear in day-to-day life and the kind of vocabulary they are exposed to at storytime. For example, we are rarely going to run into a penguin in the real world, but if we’re reading a story about life in Antarctica our children will hear a bunch of new words that will create meaning and connections in their little brains.

Logan believes the 1,483,300 estimate may even be conservative, because parents often add bits of context or embellish a story if they’ve read a book quite a few times, so our children hear even more words because we’re having some conversation on the fly.

The bottom line: A library card is cheap or free but it can be a priceless tool in setting our kids up for success.

You might also like: