Ask a six-year-old what comes after 7, and the answer is quick. Ask for 7 + 1, and the same child may start counting on their fingers from one. This 1st grade adding 1 worksheet helps your child see that the two questions are really the same. Fifteen vertical sums sit in colored boxes, each with a line to write the answer under it. In most of them, 1 sits at the bottom, like 3 + 1 or 9 + 1. In others, 1 moves to the top, as in 1 + 4 or 1 + 9, and every total stays within the sums to 10. A second page gives the answer key.