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: Stage 2: Describe the Flat Shape
Required Preparation
Materials to Gather
Play dough or modeling clay
Straws
Materials to Copy
Blackline Masters
Build Shapes Stage 1 and 2 Cards

Narrative
Students choose a shape card and describe the shape to their partner, who builds the shape based on the description.
Additional Information
Bag of straws per group of 2 students:
At least 6 straws in each size:
\(\frac{1}{2}\)
inch
1 inch
\(1 \frac{1}{2}\)
inch
\(2 \frac{3}{4}\)
inches


aligns: no