Using the Ladder Method in Middle School Math, for GCF, LCM, Factoring

Do you use the ladder method in middle school or elementary math, to find GCF, LCM, or for any other math concepts?

If you haven't had the chance to use the ladder method (or the upside down birthday cake method, as some call it), I highly recommend it.

Ways to Use the Ladder Method
As you can see in the anchor chart (sorry it's not as pretty as some!), math students can use the ladder method for:

• finding greatest common factor (GCF)
  
• finding least common multiple (LCM)  
  
• factoring
  
• finding lowest terms fractions 
  
• finding prime factorization
  
• finding the least common denominator (not pictured)! 
  

So many uses!

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Benefits of  Using the Ladder Method

1) What I really love about this method is that the process is the same for each use; the outside numbers are just used differently. I love the fact that the continued use of the ladder method (for various math concepts) leads middle school math students to make greater connections between numbers.....and finding factors seems to come more easily.

2) In addition to helping math students find GCF and LCM, using the ladder method helps students see the relationships between numbers more clearly. It's very easy to see what factors the numbers have in common and how those factors 'contribute' to the LCM or GCF.

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​Ladder Method for Factoring

When I started using the ladder method for factoring,  students picked up the factoring concept MUCH more quickly than when I hadn't used it. 
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The steps to use the ladder method for factoring are:
 1) Put the expression into the ladder.
2) Take out the common factors, one at a time (common factors go outside the ladder, then divide each number in the expression by that factor and put the quotient below the numbers in the ladder. Repeat until all common factors have been 'removed.') 
3) Multiply the numbers on the left of the ladder - these are the GCF and go outside the parenthesis in the factored expression.
4) Put the numbers at the bottom of the ladder into the parenthesis.

The short video below demonstrates how to factor a simple expression.

Ladder Method Resources

Ladder Method Fold it Up

Several years ago, I wrote a guest post about the ladder method on the Minds in Bloom blog, so if you're interested in reading more, check it out here. 

​I shared a ladder method fold-it-up in my guest post, but you can also click the button below, if you'd like to download it.

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Download the Ladder Method Fold it Up

Ladder Method Doodle Notes

I've also created a fun Doodle Notes page to help students with the Ladder Method!
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Select the button below to see the Ladder Method Doodle Notes on TPT.

If you've used the ladder method before, I'm sure you understand why I love it:-)

If you haven't used the ladder method yet, I hope you'll give it a try!

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See the Doodle Notes on TPT

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