Add Multiples of 10 using the Make 100 Strategy 2-84
Add multiples of 10 by generalizing from the Make 10 strategy to the Make 100 strategy. What's 80+60? First make 100, then add the rest. Think of 60 as 20 and 40. Since 80+20 = 100 and 100+40 = 140, 80+60 = 140. Start by modeling numbers concretely with Base 10 discs and ten frames. Transition to number bonds.
