• I can tell an addition equation from a story where a group grows

• I can tell a subtraction equation from the same story when the group returns to its starting amount

• I can explain why the two equations bring the group back to where it started

• I can create a story that starts with removing an amount and then adding the same amount back

Success Criteria

Lesson 1: Using Stories to Show Addition & Subtraction Together

We are learning that a story where a group grows and then goes back to its starting amount uses an addition and a subtraction that undo each other.

• I can split a collection into two parts and show it as an addition using both parts and the whole

• I can pull the two parts apart and push them back together to show the whole stays the same

• I can find the matching subtraction equation for a collection by removing one part completely

• I know that a collection can be moved and changed, unlike a picture or story which stays fixed

Success Criteria

Lesson 2: Using Collections to Show Addition & Subtraction Together

We are learning to show the same collection as both an addition and a subtraction by splitting it into two parts and rejoining or removing them.

• I can write the addition equation for a bar model showing two parts and a whole

• I can write the related subtraction equation from the same bar model, without building it again

• I can fill in the missing parts of a bar model before writing both equations

• I can find the related subtraction for larger numbers, such as those built from bar models to 100

Success Criteria

Lesson 3: Using Bar Models to Show Addition & Subtraction Together

We are learning to write a subtraction equation that matches an addition equation shown in the same bar model.