Add Multiples of 10 using the Make 100s Strategy 2-85
Generalize from making 100 to making 100s – multiples of 100. What's 350+80? First make 400, then add the rest. Think of 80 as 50 and 30. Since 350+50 = 400 and 400+30 = 430, 350+80 = 430. Start by modeling numbers concretely with Base 10 discs and ten frames. Transition to number bonds and equations.
