Multiple Digit Addition Strategies

Second graders have spent lots of time this year understanding many strategies and ways to show addition and subtraction with multiple digits up to 1,000. We are seeing a great understanding of the conceptual process - what is really going on with these numbers - when paying attention to place value. At times we hear (and understand!) the question, "When can kids just learn to carry the 1 like we did in the '90's?" The time is now!

We will be learning the traditional problem solving strategy (kids will be calling this "vertical form") where we line up the two addends vertically, start in the ones place, and work from right to left, top to bottom. Many parents learned this method when they were in elementary school. We wanted to note a small detail to clear up potential confusion: there are two accepted ways to "carry the 1" with our Eureka Squared math curriculum. One of the ways is above the next column, and the other way is below the next column, intersecting with the equal line. We told students that they may choose the way that helps them not to forget to add it along with the others in that column! Here's a picture of the two accepted ways. 

We love this method, and so do the kids, as it's very efficient, and we all know that second graders love to be fast. However, it's really been fun to see student work where we can see kids learning this quick algorithm while also understanding the concepts behind what's going on with these numbers. Maggie was kind enough to share her work with us last week. We love seeing these math minds grow!