56 worksheets have your students solving addition, subtraction, missing addend, and two-step word problems to 20 using several strategies: draw a picture, use a number bond, use a number line, show in ten frames, solve with doubles, doubles plus/minus one, use fact families, solve equations, and write the final answer in a sentence! Also included in the missing addend set: Single and double ten frame mats, a part/part/whole mat, an addend/addend/sum mat, and a number bond mat. Please click on