A recent study from the National Retail Federation found that the average American family spent about $700 back-to-school items this fall. While that’s a hefty number, keep in mind that it only accounts for things like clothing, electronics, notebooks and pens. As any parent with kids in school will tell you, there are a lot more education-related expenses than that — and they keep on coming well into the school year. Here are some ways to budget for the unexpected costs of having kids in school.