Addition and Subtraction Within 20

Addition and Subtraction Within 20

Course overview

This course helps Grade 1 students understand addition as joining, subtraction as taking away, and one-step word problems within 20. Students watch short video moments, talk through examples, and practice the language of each operation.

What students will learn

• Join two parts to make a total within 20.
• Take away from a whole set to find what remains.
• Decide when a story needs addition or subtraction.
• Write an equation that matches a one-step word problem.
• Explain an answer using the words join, take away, total, and difference.

Lessons

• Addition as Joining - Learn how two parts become one total.
• Subtraction as Taking Away - Learn how to find what is left after some are removed.
• One-Step Word Problems Within 20 - Learn how to choose the right operation from a short story.

Parent guide

Work through the course in short, concrete sessions with counters, drawings, or snack-sized examples. Ask the student to say the action in the story before naming the operation, and have them explain how they know the answer is correct.

Completion

A student finishes this course when they can join and separate sets within 20 and solve a one-step word problem by choosing the correct operation and equation.