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 activity is for students to choose from activities that offer practice adding and subtracting within 10. Students choose from any stage of previously introduced centers.
Shake and Spill
Compare
Number Puzzles
Required Materials
Materials to Gather
Materials from previous centers
Required Preparation
Gather materials from previous centers:
Shake and Spill, Stages 3–5
Compare, Stage 1
Number Puzzles, Stages 1 and 2
Launch
Groups of 2
“Now you are going to choose from centers we have already learned.”
Display the center choices in the student book.
“Think about what you would like to do.”
30 seconds: quiet think time
Activity
Invite students to work at the center of their choice.
10 minutes: center work time
Student Facing
Choose a center.
Shake and Spill
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Compare
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Number Puzzles
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Activity Synthesis
Display nine red counters and cover five yellow counters with a cup.
“We are playing with 14 counters. How many yellow counters are under the cup? How do you know?”


aligns: no