Maryland Math 6.NOS.B.4.a

Math6th GradeNumber and Operation Sense

The Standard

Identify the greatest common factor of two whole numbers within 100.

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: Find the largest number that divides each of two whole numbers up to 100 with no remainder. They can list factors or use factor pairs to compare the numbers.
What Mastery Looks Like: Given 24 and 36, a student identifies 1, 2, 3, 4, 6, and 12 as shared factors, then chooses 12. They can explain why 12 is the greatest.
Common Misconceptions: Students may list multiples instead of factors or choose the smallest shared factor, often 1. Some choose a number that divides only one number or assume every pair shares a factor greater than 1.
How to Assess It: Exit ticket: Find the greatest common factor of 28 and 42. List the factors you checked and explain why your answer is the greatest.

Lesson moves

Give students 24 red and 36 blue cubes; build equal-length trains using every cube and find the longest length both colors allow.
Ask: A classmate says 12 is the greatest common factor of 18 and 24. What would you say? Use factor lists.
Give pairs cards (18, 24), (15, 28), and (30, 45); students race to match them with factor cards 6, 1, and 15.
Ask how many identical snack bags students can make from 30 crackers and 45 grapes, using every item; have them describe each bag.

Free download

$Preview of the 6.NOS.B.4.a printable worksheet$

A ready-to-print activity worksheet aligned to 6.NOS.B.4.a, 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.