Unit Plan 30 (Grade K Math): Compare & Justify (0–20)

Focus: Compare sets and numerals within 0–20; justify using matching, counting, and ten-frames with clear math talk.

Grade Level: K

Subject Area: Mathematics (Counting & Cardinality)

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

I. Introduction

Students learn to compare both quantities and numerals to decide which is greater, less, or equal. They practice three proof moves: match items one-to-one, count to compare, and use ten-frames to see 10 and some more. Emphasis is on explaining why a comparison is true.

Essential Questions

• How do I know if one set is greater, less, or equal to another?
• When should I use matching, counting, or a ten-frame to compare?
• How can I explain and justify my comparison so others understand?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Compare sets (0–20) using matching (one-to-one) to show more/fewer/same.
2. Count and compare (0–20) and tell which numeral/set is greater, less, or equal.
3. Use ten-frames to compare teens by seeing 10 and some more.
4. Explain comparisons with clear language and evidence (model, count, or ten-frame).

Standards Alignment — CCSS Kindergarten (threaded across the unit)

• K.CC.6: Identify whether the number of objects in one group is greater than, less than, or equal to the number of objects in another group (e.g., by matching and counting).
• K.CC.7: Compare two numbers (as written numerals) between 1 and 10. (Extended in class routines to 0–20.)
• Mathematical Practices: MP.6 (precision), MP.3 (construct arguments & critique), MP.2 (reason quantitatively), MP.7 (look for structure).

Success Criteria — Student Language

• I can match items to see same, more, or fewer.
• I can count two sets and tell which is greater or less.
• I can use a ten-frame to justify my comparison.
• I can explain why my comparison is true.