Call Us877-601-6284
Get Started by Finding a Local Center
Blog / Mathnasium #MathTricks: Divisibility (Rule for 3's)

Mathnasium #MathTricks: Divisibility (Rule for 3's)

Oct 29, 2021 | A+

A number is divisible by 3 if the sum of the digits is divisible by 3.

To determine if the number 87 is divisible by 3, we find the sum of its digits. Eight plus seven gives us a final sum of fifteen. Fifteen is divisible by 3. So,

87 is divisible by 3.

Click here for more practice problems!

SEE HOW MATHNASIUM WORKS FOR YOUR SITUATION

Answer a few questions to see how it works

My Child is:

  • Icon of a happy person on red background

  • Advanced in Math
  • Icon of a woman on grey background

  • Doing Ok, Could Do Better
  • Icon of a man on yellow background

  • Struggling with Math
Cloud
Cloud

OUR METHOD WORKS

Mathnasium meets your child where they are and helps them with the customized program they need, for any level of mathematics.

Icon of toddlers

Early Learners
Icon of elementary school students

Elementary School
Icon of middle school students

Middle School
Icon of students

High School
Find Their Path Arrow

Related Articles

Why Math Feels Harder for Kids with ADHD And What Helps

Aug 28, 2026 |

Mathnasium education specialists explain why the ADHD brain finds math harder and share 5 research-backed strategies parents can use at home today.

The Mathnasium Advantage: Choose the Best For Your Child

Aug 3, 2026 |

Discover how the Mathnasium Method™ builds lasting math skills, confidence, and true understanding – offering more than traditional private tutoring.

5 Tips to Help Your Child Develop Good Study Habits

Aug 3, 2026 |

Another school year is here. Is your child ready? When it comes to studying, kids need to have good habits to start the year off right and stay on track. Good study habits will build strong math students and instill a positive outlook on their learning, w..

HELP YOUR CHILD ACHIEVE THEIR FULL MATH POTENTIAL

We have nearly 1,000 neighborhood centers nationwide. Get started now.

  • Find a location
  • Get a math skills assessment for your child
  • Your child will complete a customized learning plan
Get Started by Finding a Local Center
Mathnasium Logo
Download Parent Pack
©2026 Mathnasium Franchisor LLC. All rights reserved.
Loading