When his third-grade teacher sends him back to the bus for having caused trouble while on a school field trip, Spider makes an amazing discovery about the driver.
Text and photographs follow Mrs. Kramer, a safe and careful bus driver, as she gets the children to school on time and brings them home again at the end of the day.
When the regular schoolbus is in the shop, a clever driver must use all that he knows about addition and subtraction to ensure that seventy-six children get on--and off--of the four-seat substitute bus.