1.OA.C.6 Worksheet: Computation Skills — Grade 1 Aligned

This Grade 1 math assessment helps students demonstrate mastery of addition and subtraction within 20. Through structured computation and word problems, students solidify operational fluency. This printable PDF is a reliable measure of key foundational math skills, ready for classroom use.

At a Glance

• Grade: 1 · Subject: Math
• Standard: CCSS.MATH.CONTENT.1.OA.C.6 — Add and subtract within 20, demonstrating fluency for addition within 10.
• Skill Focus: Mixed Addition & Subtraction
• Format: 5 pages · 29 problems · Answer key included · PDF
• Best For: Summative assessment, skills review, test prep
• Time: 20–30 minutes

What's Inside

This five-page resource is a complete computation test. It starts with addition and subtraction within 10, then moves to a mixed challenge section up to 20. It concludes with word problems to assess application. A full answer key is provided for easy grading.

Evidence of Mastery

This assessment directly maps to CCSS.MATH.CONTENT.1.OA.C.6, producing clear evidence of student proficiency. The task sequence—from simple fluency to mixed operations and word problems—allows teachers to pinpoint specific strengths and weaknesses. The final score serves as a reliable data point for report cards or standards-based gradebooks.

Standards Alignment

This worksheet is aligned to CCSS.MATH.CONTENT.1.OA.C.6, requiring students to "Add and subtract within 20." It also supports CCSS.MATH.CONTENT.1.OA.A.1 by asking students to solve word problems. Both standard codes can be copied directly into lesson plans or curriculum maps.

How to Use It

Use this worksheet as a summative assessment after your unit on addition and subtraction, taking 20-30 minutes. For formative data, observe students during the "Mixed Challenges" section. Hesitation or finger-counting indicates a need for more fluency practice. The word problems can check comprehension.

Who It's For

This is ideal for first-graders learning addition and subtraction within 20. Use it as a pre-assessment for second grade or for review. For differentiation, provide a number line or physical counters for students needing concrete support to complete the problems successfully.

This Grade 1 computation assessment provides targeted practice aligned with CCSS.MATH.CONTENT.1.OA.C.6, focusing on adding and subtracting within 20. The worksheet's structure, progressing from basic fluency to applied word problems, reflects effective instructional design for building procedural skill and conceptual understanding. Research emphasizes the importance of fluency in early math development as a foundation for more complex problem-solving. The `RAND AIRS 2024` report highlights that structured practice with clear progression is critical for developing these automatic skills. This assessment offers a valid instrument for teachers to measure student mastery of this key first-grade standard, providing data that is essential for guiding instruction and intervention.