Monday, January 14, 2013

Lattice Addition!

I have been working on my geometry puzzles but I need a break, that baby is intense! 

So, I am sure that this topic will spark some debate since so many folks have an opinion on math strategies.  Keep in mind, my philosophy is I feel it is important to give students LOTS of tools for the toolbox, especially in math since they will be challenged at some point.  My goal is to teach students to be problem-solvers, that way they are learning a life-long skill. 

That brings up the first strategy I show students, Lattice.  Yes, I show it to middle school students too.  Lattice multiplication is the first lesson I teach during the first week of school in sixth grade.  I know you are thinking...gosh they should be able to multiply by sixth grade.  News flash....Some still can't.  I start with this lesson because some of my high kids struggle some since it's not the "standard way", but my struggling learners find success (on the first day of school), which I find very important.  Before I show y'all how to multiply using Lattice, I will show Addition using Lattice since many of my followers are primary teachers. 

Let's start with an easy one...
78 + 84

1.  Write the addends in the lattice.
2. Add the columns.  Write the tens digit in the upper left triangle and the ones digit in the lower right triangle. 
3.  Add diagonally starting on the right side.  If a tens digit occurs, regroup it into th next diagonal.  Write the sum in the blank.

I know many of you are thinking this may confuse them more than help them.  Well, I would not show all my kids this if it is a year that they are first exposed to the algorithum.  I teach the standard way, but when I am in small group and students are still struggling - I teach them this method.  I figure it can't hurt if they have been struggling for some time with the standard way.  My goal is to teach kids that there are many ways to solve a problem (or as mom says, "To skin a cat!")

Here is a practice sheet, click on the image to download this Freebie!

Next time, 3x2 and 2x3. 


  1. This is a very cool math idea. I am not sure if you teach middle school math. I have looked all around your blog. If you do please consider linking up to my Middle School Blog Log.
    I just found your blog via Farley. Check it out and let me know if you want to be added. Thanks!

  2. Would love to link up! I taught middle school for 6 years, and then became math specialist for grades 3-8
    On my way to check it out.

  3. I love this! I am becoming a math teacher and I would totally do this!