Category Archives: Math Minute

#83 The Luhn Algorithm

The Luhn algorithm or Luhn formula, also known as the modulus 10″ or “mod 10” algorithm, was developed in the 1960s as a method of validating identification numbers.  Number communication accuracy can be using this formula

Take time to explore:

Read this article about the formula and how it is used in real life to catch errors when shopping online.  Research the creator Peter Luhn and make a timeline about his life.

In this video you will learn how to use the Luhn Algorithm. Make the table on paper as you watch.

Math challenge presented by CEMC math POTWC-20-NN-PA-21-P . Print it out, read the page and look at the different strategy that they present to you. Try to figure out the last challenge. Answer key for challenge. You can use this to check you work.




#82: EWeek 2021

Do some math problems and earn PRIZES!

Engineers Week (EWeek) is THIS WEEK and you can celebrate with MATHCOUNTS by solving their 5 Problems of the Day (linked below).  BONUS: Just for participating, you’ll have an opportunity to earn some prizes!

  • Each day you’ll have an opportunity to solve our Problem of the Day and enter a prize drawing! You can submit your answers anytime during EWeek (Feb 21-27), so don’t panic if you get started late! Each Problem of the Day has multiple parts, and each correct answer you get will be a ticket in that day’s prize drawing.
  • Everyone who participates will be entered in a prize drawing! Submit answers to at least one Problem of the Day and you’ll be entered to win, even if you don’t get correct answers.
  • Each individual prize drawing winner will get a $10 Amazon gift card and each group drawing winner will receive a $50 gift card to the MATHCOUNTS store!

Monday’s Problem (Environmental Engineering):

Tuesday’s Problem (Systems Engineering):

Wednesday’s Problem (Software Engineering):

Thursday’s Problem (Aerospace Engineering):

Friday’s Problem (Chemical Engineering):

#81 Triangular Numbers

Have you seen a question like this before?

How can you solve this problem without drawing a picture on paper?

Use one of the resources below to solve the problem.

  • Use this interactive tool to construct triangular numbers until you can see the pattern to answer the counter question from above.

  • ADVANCED: This is a teaching page that REALLY gets into the math behind these types of problems. Use the formula and see if you can get the right answer.

  • Check out this triangular number chart.  Click on getting started. When you have a solution and a written statement about what you did to solve the problem, check the “solution” button to check your work.

  • Connection: Research the original Light Brite, a 1960s toy. Come up with some unique idea on how teachers can use these toys to teach math, science, and art.


Image source:

#79 Really Big Numbers

What is the biggest number you can think of?  What does that number mean?  For this math mini spark, you will be exploring some “really big numbers” and what they mean.
In your math notebook, complete the following tasks:
  • In the episode, “Have You Seen This Snail?”, SpongeBob SquarePants is given a challenge of hitting a paddle ball 29,998,559,671,349 times in a row.  This causes SpongeBob to neglect Gary (his pet snail) and so Gary leaves.  Write this number out in words.

image source:

Thank you for inspiring this this math mini spark.  It definitely sparked my curiosity!

# 77 Organizing Data

We are surrounded by information (data) and it’s important to organize it into presentable and easy to understand ways!
For this spark, you are going to display some information.  You can choose the topic and the way you represent it.   You must also include 5 questions that can be answered from your information.
If you need some inspiration, you can watch The Great Graph Contest.

#76 Bedtime Math

Each day you can find a NEW math post at Bedtime Math to stretch your math thinking.

Check out this post about the world record cat, Sophie!


September 4, 2020

Sure, most cats are soft and furry. But this one has gone bonkers. Sophie holds the world record for the longest cat fur. Measuring more than 10 inches long, Sophie’s fur might be longer than your own hair. Judging from the look on her face, we’re not sure she likes having all that fur…and you can’t blame her. Her owners have to brush her out 2-3 times every week to keep it neat. But now that she holds the Guinness World Record for furriest cat, maybe it’s worth it.

Your Turn

1. Create a pic collage with the topic from this and some of the facts from the article. Do a bit of research to add a few more bits of information related to the topic.

2. Choose a math question to answer from the list below depending on your age.

3. Add question and the the answer to your pic collage.

4. If you want to do more of these challenges, add the Bedtime Math site to your homescreen on your ipad.

Little kids: The previous record holder, Colonel Meow, had fur 1 inch shorter than Sophie’s. How long was Colonel Meow’s fur?  Bonus: They say eating salmon (a type of fish) makes your hair soft and healthy. If Sophie eats salmon twice a day, how many times does she eat it in a week?

Big kids: If Sophie’s fur grows 1 inch every 2 months starting now, could it be 14 inches long by next May? (We’re starting September now.)  Bonus: If Sophie needs 2 more brushings this week (Wednesday through Saturday) on any 2 days, how many different pairs of days could she be brushed?

By Laura Overdeck

#75 Make Anything into Math

You know, you can think of almost anything as a math problem!

Check out this video
~Ms. Fibonacci from Math Curse

While you’re out and about over the weekend, take a snapshot of anything that reminds you of a math concept/problem.  Create a pic collage or another visual of your choice with your picture and a math problem goes along it. Create an answer key as well. Send a your problem and key to the EY teacher at your school.

#74 Fibonacci Fun


The Fibonacci Sequence

1, 1, 2, 3, 5, 8, 13, 21, 34, 55…

The Fibonacci Sequence is a simple sequence of numbers that anyone can learn!  This Math Minute has you exploring some Fibonacci Fun.

How can I spend my math minutes?
  • The list above includes the first 10 terms of Fibonacci’s Sequence.  Write out the next 10, 20 (or more) terms by adding the 2 previous numbers (i.e. the next Fibonacci number is 34 + 55 which is 89).  Yes, I’m aware you can just find a website that lists out the Fibonacci numbers so all you have to do is copy them down, but instead of copying them down, practice your basic math skills and DO the math yourself!
  • “Too much of the mathematics we learn in school is not effectively motivated.” ~Mathemagician Arthur Benjamin Watch his TED Video about the Magic of Fibonacci Numbers at
  • Watch this Numberphile video about Random Fibonacci Numbers.  Then, try the activity he explains in the video using a coin.  My sons Toby and Trevor and I recorded ourselves doing the activity here:
  • Read about the Fibonacci Sequence at Math is Fun and leave a comment about something new you learned.

Image of Golden Spiral: “Fibonacci” by Sam Felder is licensed under CC BY-SA 2.0