Unit Plan 20 (Grade K Math): Teen Numbers—Represent & Compare

Focus: Represent teen numbers (11–19) with ten-frames and cubes; explain that each teen is one ten and some ones, and compare teen numbers by the ones.

Grade Level: K

Subject Area: Mathematics (Number & Operations in Base Ten; Counting & Cardinality)

Total Unit Duration: 5 sessions (one week), 30–40 minutes per session

I. Introduction

Students extend teen-number work by building and drawing one ten and some ones, then comparing teen numbers. Because all teens have one ten, students learn to decide “which is more/fewer” by looking at the ones only. They use ten-frames, bundles of ten, and explanations to justify comparisons.

Essential Questions

• How do ten-frames and cubes help me show a teen number?
• Why can I compare teens by looking at the ones?
• How can I explain which teen is more, fewer, or the same?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Represent any teen number (11–19) as one ten and n ones using ten-frames and cubes.
2. Record or tell a matching equation idea (10 + n) or sentence (“14 is 10 and 4 ones”).
3. Compare two teen numbers using more/fewer/the same, explaining that tens are the same so the ones decide.
4. Use place-value and comparison language in clear, complete statements.

Standards Alignment — CCSS Kindergarten (threaded across the unit)

• K.NBT.1: Compose/decompose 11–19 into ten and some ones; show with drawings/recordings (e.g., 18 = 10 + 8).
• K.CC.6–7 (within 20): Compare numbers/sets and compare written numerals; use more, fewer, equal.
• Mathematical Practices: MP.7 (look for/use structure) emphasized; MP.2, MP.6 threaded.

Success Criteria — Student Language

• I can show 15 as 10 and 5 ones on a ten-frame or with cubes.
• I can tell or write 10 + 5 to match my model.
• I can say which teen is more/fewer and explain, “Both have one ten; __ has more ones.”