# Additive Thinking

Although the Additive Thinking section is not yet ready, we wanted to add some videos you might find helpful.

**Pocket Subtraction – when the Minuend ends in Zero**

This strategy is useful in subtraction questions where the “starting” number ends in a zero.

*The correct name for this strategy is “Compensation”. You change one of the numbers (in this case the minuend), in order to make solving the question easier.*

**Pocket Subtraction – when the Subtrahend ends in 9**

This strategy is useful in subtraction questions where the number that is being subtracted ends in 9.

*The correct name for this strategy is “Compensation”. You change one of the numbers (in this case the subtrahend), in order to make solving the question easier.*

**Adding 2 Digit Numbers – without regrouping**

This video is Part 1 of the 2 part series “Addition of 2 Digit Numbers – Partitioning by Place Value”. Part 1 focuses on building and solving 2 Digit Addition questions that do not require regrouping. You will then compare this method to the traditional algorithm.

You will need access to one of the following:

- Physical Base Ten Blocks (tens and ones)
- Printable Base Ten blocks (print in black and white OR color)
- Virtual Base Ten Blocks e.g. CPM Tiles

*The correct name for this strategy is “Partitioning by Place Value”. *

**Adding 2 Digit Numbers – with regrouping**

This video is Part 2 of the 2 part series “Addition of 2 Digit Numbers – Partitioning by Place Value”. Part 2 focuses on building and solving 2 Digit Addition questions that require regrouping. You will then compare this method to the traditional algorithm.

You will need access to one of the following:

- Physical Base Ten Blocks (tens and ones)
- Printable Base Ten blocks (print in black and white OR color)
- Virtual Base Ten Blocks e.g. CPM Tiles

*The correct name for this strategy is “Partitioning by Place Value”. *