Curriculum placement
Grade 1. This describes the skill, not a learner estimate.
Equations for addition and subtraction stories
Choose an equation for joining comparing or part-whole stories
Problem types
- Match a story and a number sentence within 20
- Choose the equation for a story
- Find the starting amount
Builds on
- Adding within 20
- Reading a categorical graph · Useful idea
Questions about a picture graph, such as how many in all, are addition stories about the categories.
- Join and separate: pictures, equations · Earlier idea
Reading a picture of joining or taking away as a number sentence is the first step. Addition stories ask for the number sentence of a longer story, including stories that compare two groups.
Leads to
- Two-step word problems
- Multiplication and division word problems · Extend the idea
Choosing the operation from a story begins with joining and separating. Later stories add equal groups, where the story still decides whether to add, subtract, multiply or divide.
- Profit, cost, and taxes · See it applied
Profit stories join and separate money amounts: income is added, cost is taken away, and the difference tells whether there is a gain or a loss.
- Word problems with signed numbers · Extend the idea
Stories about joining and separating extend to gains and losses, where the amounts can be negative or fractional.
Related skills
- Add two-digit numbers · Shared foundations
- Counting on and counting back · Shared foundations
- The meaning of the equal sign · Shared foundations
- Subtracting within 20 · Shared foundations
- Adding three numbers · Shared foundations
Open the interactive map to explore lessons and skill connections.