Introduction to Multiplication Ideas

Multiplication is one of my favorite math units to teach! I remember what a big deal it was to learn multiplication when I was in school and the kids still feel the same way. When I ask them at the beginning of 2nd grade, what they are most excited to learn - multiplications tends to be one of the most popular answers.

To begin multiplication, I want to make sure my students have a solid conceptual understanding of the process. When I was a kid we just memorized the facts. And, while fact fluency is important.  In my opinion, it's important that they first understand why and how to multiply, before they rattle off the facts from memorization.  I've also been trained in CGI (Cognitively Guided Instruction), which focuses on conceptual understanding and moving kids through different stages of understanding which ultimately leads to fact fluency.  These ideas below definitely fit in with CGI.

So, on day 1, I started by giving them a story problem.  

There were four spiders crawling in the sand. Each spider has 8 legs. How many legs were there total?

I wanted to see what the kids would do. I didn't tell them this was a multiplication problem, I just read it to them, and told them to solve it the best they could.  Then, as I walked around, I picked students with different strategies who would share out with the class.  

Here are the 3 I picked to share:

Carter started by drawing the groups in the middle. He drew one group of 8, two groups of 8, so on and then added and added again.  Great visual strategy!

Odin used skip counting and also used empty number line to help him show how he was skip counting. 

Caitlin used repeated addition, which is another great multiplication strategy.

I picked all three kiddos because these are all strategies we are going to learn to help us solve multiplication problems. I love having the kids explain their thinking too because kids often learn better from each other - if they hear it in kid friendly language etc. I asked prompting questions, but the kids did the explaining.

Then, on day 1, I wanted our focus to be on grouping like Carter did in his story problem. I wanted to start with the most visual representation possible to help the kids see the equal groups.

We made an anchor chart - which I forgot to snap a picture of and then we practiced on our white boards.  

I love being able to project my iPad onto our screen. I use the app iPevo and can use it like a white board like the kids.  So, we started with visual problems. Sorry for the messy iPad demonstration - it is quite difficult to draw using your finger on there. :-)

After practicing multiple problems as a class, students learned the game Circle in Stars or Birds in a Nest.

For this game, students need 1 or 2 dice, white board and marker and/or paper and pencil. Students roll one dice and that is the number of circles (or nests) they draw (which is really the number of groups).  Then, students roll again or roll the second dice and that is the number of stars (or eggs) that go in each circle.  Which then leads to the multiplication problem ___ groups of ___ = ___ or ___ x___ = ____.  To differentiate for my higher students, I gave them a dice with 1-6 and one with 7-12.  This takes it up a notch for students who are ready.

With dice 1-6

With two dice - 1-6 and 7-12

How do you start teaching your multiplication unit?? Leave your thoughts and ideas in the comments below...