standard_description: Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:
- The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.
- The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).
- 10 can be thought of as a bundle of ten ones — called a “ten.”
problem_activity: Narrative
The purpose of this What Do You Know About _____? is to invite students to share what they know and how they can represent the number 20.
Launch
Display the number 20.
“What do you know about 20?”
1 minute: quiet think time
Activity
Record responses.
Student Facing
What do you know about 20?
Student Response
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Activity Synthesis
“What connections do you see between different answers?”
Pick two addition expressions that use different addends and ask, “How are these two expressions related?”


aligns: no