Maryland Math 6.NOS.B.2.d

Math6th GradeNumber and Operation Sense

The Standard

Determine and explain when a strategy or algorithm is most efficient.

Maryland College and Career Ready Standards for Mathematics (2025) · COMPUTE FLUENTLY WITH MULTI-DIGIT NUMBERS AND FIND COMMON FACTORS AND MULTIPLES.

Teacher's field guide

What Students Need to Do: Students choose methods for multi-digit calculations and for finding common factors or multiples. They compare methods and explain which one takes less work for the numbers given.
What Mastery Looks Like: A student solves 48 × 25 as 12 × 100 and explains why the product stays the same. They find that 12 is the greatest common factor of 24 and 36, then explain why checking factors is quick for these numbers.
Common Misconceptions: Students may assume the written algorithm is always the best choice. When they change 48 × 25 to 12 × 100, they may divide 48 by 4 but forget to multiply 25 by 4.
How to Assess It: Exit ticket: Solve 48 × 25 and find the greatest common factor of 24 and 36. For each, name your method and explain why you chose it over another method.

Lesson moves

Give pairs 24 counters and 36 counters; have them make equal-sized groups to find the largest group size that works for both.
Ask, "For 399 × 6, would you use 400 × 6 minus 6 or written multiplication? Why?"
Put 48 × 25, 207 × 5, and 36 × 14 on cards; pairs choose a method and defend it before calculating.
Show a store order for 96 packs of 25 pencils; ask students to choose and explain a quick way to total the pencils.

Free download

$Preview of the 6.NOS.B.2.d printable worksheet$

A ready-to-print activity worksheet aligned to 6.NOS.B.2.d, with an answer key for the teacher on its own page. No account needed.

PDF, US Letter, prints cleanly in black and white.

Keep exploring

Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.