1+-+Two,+Fives,+and+Tens

1 - Two, Fives and Tens

Twos, Fives, and Tens: Addition, Subtraction, and the Number System 4

Students revisit the number sequence as they count and write numbers to 100 and beyond. Students work on achieving fluency with the two-addend combinations of ten, they are introduced to ideas about equivalence (8 + 5 = 10+ 3), and they engage in activities that highlight the importance of ten in our Base-10 number system. As students work with contexts that provide opportunities to count by groups of 2s, 5s, and 10s, they think about ways to organize objects so that they are easier to count and combine, and they begin to make sense of what it means to count by equal groups.