2.1.G
Math2nd Grade
The Standard
display, explain, and justify mathematical ideas and arguments using precise mathematical language in written or oral communication
Texas Essential Knowledge and Skills for Mathematics
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students show how they solved a problem and explain why their method works. They use specific math words, complete sentences, labeled drawings, and equations when speaking or writing.
What Mastery Looks Like
- A student can show a solution with numbers, drawings, or objects and describe each step clearly. The student uses correct math words and answers questions such as, “How do you know?”
Common Misconceptions
- Students may give only an answer or list steps without saying why they work. They may use vague words like “it” or “that” instead of naming numbers, operations, tens, or ones.
How to Assess It
- Exit ticket: Solve 38 + 24, show your work with a drawing or equation, and write two sentences explaining why your method works.
Lesson moves
Ways to Teach It
Give pairs base-ten blocks to solve 46 + 27, then have each student point to the model and explain every step.
During a number talk, ask students to compare two strategies for 63 minus 28 using tens, ones, regroup, and difference.
Play Explanation Match, where students pair solution cards with reasoning cards, then reject one mismatched explanation using the word because.
Plan a class snack order, then have students choose between two combinations and explain their choice with numbers, labels, and comparison words.
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