Grade 1 · Number
Change in Quantity to 20
Change in quantity is addition and subtraction in story form before the symbols arrive. Start with 9. Make it 14. What changed? requires students to find the difference and describe it as an action. This verbal and concrete work makes formal equations meaningful: students write 9+5=14 because they understand what the symbols represent, not because they memorized a procedure.
LESSON VIDEO
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Lesson video
A short walkthrough to play in class or assign for flipped/at-home viewing.
WHAT STUDENTS WILL LEARN
✓Describe and model adding to or taking from sets using concrete materials to 20
✓Use language of change: I started with ___, I added/removed ___, now I have ___
✓Solve build-and-change tasks: Start with 9. Change it to 14. What did you do?
✓Connect verbal descriptions of change to symbolic equations using + and -
✓Recognize three change problem structures: unknown result, unknown change, unknown start