Informal and mental strategies for adding and subtracting two 3-digit numbers
Why this, why now
In this unit pupils will add and subtract two 3-digit numbers using partitioning, adjusting, redistribution and bridging.
Prior knowledge requirements
- Ardaydu waa inay yaqaanaan aasaaska maadada.
- Ardaydu waa inay awoodaan inay raacaan tilmaamo fudud.
Unit 8 / 20
Informal and mental strategies for adding and subtracting two 3-digit numbers
In this unit pupils will add and subtract two 3-digit numbers using partitioning, adjusting, redistribution and bridging.
10 lessons- Choose the most efficient strategy to subtract from a 3-digit number
- Subtract a pair of 2-digit numbers by finding the difference
- Subtract 3-digit multiples of 10 by finding the difference between them
- Subtract 2 or 3-digit numbers using partitioning and bridging a multiple of 10
- Use addition and subtraction to solve problems in different contexts
- Choose the most efficient strategy to add two 3-digit numbers
- Use addition and subtraction to solve problems involving bar charts, pictograms and tables
- Add two 3-digit numbers using adjusting strategies
- Add two 3-digit numbers using partitioning
- Add 2 and 3-digit numbers by redistributing