Subject
Grade
Concept/Content
addition and subtraction to 100
Elaboration
- decomposing numbers to 100
- estimating sums and differences to 100
- using strategies such as looking for multiples of 10, friendly numbers (e.g., 48 + 37, 37 = 35 + 2, 48 + 2 = 50, 50 + 35 = 85), decomposing into 10s and 1s and recomposing (e.g., 48 + 37, 40 + 30 = 70, 8 +7 = 15, 70 +15 = 85), and compensating (e.g., 48 + 37, 48 +2 = 50, 37 – 2 = 35, 50 + 35 = 80)
- adding up to find the difference
- using an open number line, hundred chart, ten-frames
- using addition and subtraction in real-life contexts and problem-based situations
- whole-class number talks
keywords
addition and subtraction to 100