Maryland Math 2.NOS.B.6.a
The Standard
- 2.NOS.B.6
- Recall or quickly derive addition and subtraction facts within 20.
Use counting, make ten, and ten more/less, doubling strategies to add and subtract.
Maryland College and Career Ready Standards for Mathematics (2025) · ADD AND SUBTRACT WITHIN 20.
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students add and subtract within 20 by counting on or back, making ten, using doubles, or finding ten more or ten less. They show their thinking with counters, drawings, or equations.
What Mastery Looks Like
- A student can solve 8 + 5 as 8 + 2 + 3 and explain why the answer is 13. They can use 7 + 7 to solve 7 + 8 and find 17 - 10 without counting every number.
Common Misconceptions
- Some students start counting both groups from one instead of counting on. To solve 13 - 5, they may subtract 3 to reach ten, then subtract another 5 instead of the remaining 2. Others confuse ten more with one more.
How to Assess It
- Exit ticket: Solve 9 + 6 and 16 - 10. Draw or write how you made ten for the first and found ten less for the second.
Lesson moves
Ways to Teach It
Give pairs two ten-frames and 15 counters; have them build 9 + 6 by moving one counter to fill the first frame.
Ask, 'How does 7 + 7 help you solve 7 + 8?' Have students write both equations and explain the extra one.
Deal pairs cards numbered 0 to 10; students add them and say whether they counted on, made ten, or used a double.
Set out 14 pencils, then put 10 away; ask students how many remain without counting every pencil.
Free download
Printable 2.NOS.B.6.a Worksheet
A ready-to-print activity worksheet aligned to 2.NOS.B.6.a, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetKeep exploring
Related Standards
- 2.NOS.C.8.a
Use strategies based on counting (e.g., counting on, counting back) and place value (e.g., partial sums, making tens, etc.) to add and subtract.
- 1.NOS.E.10.b
Use counting strategies and strategies based on place value (e.g., partial sums, making tens, etc.) to add.
- 2.NOS.C.9.b
Use strategies based on place value (counting on, partial sums, making tens, etc.) to add and subtract.
- 1.NOS.D.9.c
Use the ten more and ten less strategies to add and subtract (including those with a difference of 10).
Turn this exact standard into a lesson
Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.
Also for this standard:Make a WorksheetMake a QuizMake a Sub Lesson