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”.