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.
It can be used for several different concepts and has some great benefits for students.
What Concepts Can the Ladder Method Be Used With?
The ladder method can be used for quite a few concepts. As you can see in the anchor chart below (sorry it’s not as pretty as some!), upper elementary and middle school math students can use the ladder method for:
- finding greatest common factor (GCF)
- finding least common multiple (LCM)
- finding lowest terms fractions
- finding prime factorization
- finding the least common denominator (not pictured, but you can read about it in the linked post)!
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 continually using the ladder method (for various math concepts) leads middle school math students to make greater connections between concepts. Finding factors also 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.
Using the 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.
The steps to use the ladder method for factoring are:
- Put the expression into the ladder.
- 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.’
- Multiply the numbers on the left of the ladder – this is the GCF, which goes outside the parenthesis in the factored expression.
- Put the numbers at the bottom of the ladder into the parenthesis.
You can see this process shown on the Fold It Up below.
Ladder Method Resources
Ladder Method Doodle Notes
I’ve also created a fun Doodle Notes page to help students with the Ladder Method!
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!