The purpose of this activity is to develop useful strategies for mental calculation when estimating possible addition solutions.
NA2-1: Use simple additive strategies with whole numbers and fractions.
Specific Learning Outcomes
estimate the sum or difference between numbers.
Required Resource Materials
- Draw this chart on board
- Tell the class that the aim of the activity is to locate pairs of numbers which fit the given criteria.
- Which pairs have a total between 250 and 300? (avoid exact sum or difference)
How do you know? How did you work that out?
- Total close to 250
- Difference close to 50
- Total close to 350
- Difference close to 75