Back from my mini-Spring Break getaway and eager to get back to work on my newest product, which features adorable monkeys and focuses on addition, subtraction, and place value. Which brings up the question, how many ways can *you* add 34 and 28? Like many of you, I was taught the traditional algorithm for adding multi-digit numbers. And when I learned it, there was not even any mention of place value–8 + 4 = 12, write down the 2 and carry the 1. Sadly, there are still teachers today who teach the algorithms for addition and subtraction in a completely rote manner.

So here’s a few different ways you might add these two numbers (adapted from Van de Walle, __Teaching Student Centered Mathematics, K-3__).

__Use multiples of 10:__I know that 20 more than 34 is 54 (give kids lots of practice doing this on a 100 chart). Six more gets me to 60, plus 2 more is 62 (notice that I broke apart the 8 into 6 and 2).__Add the tens and then the ones:__20 + 30 = 50 and 4 + 8 = 12 (I would probably think of this as 8 + 2 to make a 10 and then 2 more). 50 + 12 = 62.__Move some to make 10s:__I can move 2 from the 34 (leaving 32) to the 28 to make 30. 30 + 32 = 62.__Use friendly numbers and adjust:__28 is pretty close to 30. 30 and 34 is 64, but I have to take off 2, because 30 is 2 more than 28, so it’s 62.

Challenge your kiddos to show two different ways to add numbers!!

For more on addition, number sense, and place value check out __Monkey Business, Adding Tens and Place Value Workstation Activities__.

I just found your blog (through Pinterest) and I am so excited! I am going to use your comparing numbers work tomorrow!

Jennyfer

http://www.teachinginthecouv.blogspot.com

We teach these strategies at school (started this year) and the difference in what they can do is AMAZING! I did have to send home a note explaining that this is different than how we (the adults) learned adding.

Yes! It’s harder for the parents to accept than the students!

I’m a Singapore Math trainer. Loving what I see!!

Thank you!! I had one of my teachers asking about this just tonight!!!

I’ll be that was a great conversation! I just love thinking about computation this way.

I’m working with my 2nd graders to make some 10s to add. I have a parent who is very negative and only wants her child to learn the standard algorithm way. I have asked her to remain positive and allow me to show the students that numbers can be added in different ways. She’s very vocal, in front of the class, about this (I’m teaching virtually). Any suggestions on how to help her understand?

Ask her what her goal is for her child’s mathematics learning. Does she simply want the child to memorize procedures, or does she want the child to have a depth of understanding and be able to work flexibly with numbers? You could quote statistics that indicate that students who learn by memorization do more poorly in international testing than those who learn by exploring multiple strategies. The youcubed website has great information about why we are teaching math in a different way now!