Moving From LCM to Adding Fractions Using Legos.

 As you know, I've been playing with Legos to figure out how to use them for something other than basic fractions in lower elementary.

I already figured out how to use them to help find Lowest Common Multiples or LCM so its really not a huge step to seeing why its important to have equivalent fractions when adding.

So I used the same number of Legos for the denominator and used a second set of Legos in a different color to represent the numerator. 

As you can see in the photo above, you see the 1/4 and 1/6 quite easily.  Then using the same method I added another 1/4 and 1/4 to get 3/12 which is the correct equivalent fraction.

For 1/6, it required a second 1/6 to get a total of 2/12.  This allows students to easily see why you multiply the numerator and denominator by the same number so you end up with equivalent fractions.

The same process could be used to show subtraction as well as addition so students can see it.

If you have enough Legos, it is possible to have larger denominators such as 15, 28, or 34 and allow them to see the process works as well on larger denominators as for smaller ones.

Let me know what you think.  I'd love to hear.  My next project is multiplication of fractions and whole numbers using Legos.  As soon as I have that done, I'll share it.