Teaching the Distributive Property Through Multiplication
The math curriculum for elementary has changed tremendously. Many of the math concepts that were taught in middle school have now found a home in 3rd -5th grade. Elementary teachers have found themselves scrambling for new teaching strategies to address this shift. One of the most complicated concepts that elementary teachers have to now teach is the distributive property.
Many middle school students struggle to really understand the concept of the distributive property. So, teaching this concept to 3rd and 4th graders can be down right terrifying! Actually the material that elementary teachers were using before the shift can still be used to teach the distributive. The major difference is that we no longer focus on one strategy to solve a problem. For example, when multiplication is introduced we no longer focus on factor x factor = product. The concept of multiplication can be use to introduce 3rd graders to distributive property by using arrays to break apart the multiplication fact and then adding. This is great way to increase the rigor of the lesson but it also provides practice with multiple skills.
I have had teachers voice their concerns about confusing the students with all of the different strategies. My response to this is to use common sense. If you are teaching students who are new to this kind of thinking only introduce 2 strategies so that the students will experience some success and are still able to choose a strategy that best suits their thinking.
Place value is also a powerful concept that can open up endless possibilities for teaching math concepts to elementary students. It can also help upper elementary students understand the distributive property. On Monday, Wednesday, and Friday I have Number Talks for 7 minutes after the warm up. Last week we began multiplying 2 digit by 1 digit numbers. Implementing Number Talks is a perfect opportunity to introduce or reinforce decomposing numbers and then gradually move on connecting the distributive property.
- Begin with decomposing the 2 digit number into 2 numbers and then multiply each number by the remaining factor.
- Once the students are comfortable with this concept introduce the parenthesis. I explained to my students that parenthesis keeps things together (this was also taught with expanded notation with decimals).
- The problem should shift form decomposition to putting (20+4) into parenthesis and then leaving the 6 outside of the parenthesis.
- 6 x (20 + 4) or 6(20 + 4) some teachers put the multiplication sign but I didn’t have to do this because most of my students understood that the 6 would be multiplied because of the reference from the original problem.
One of my 5th grade students gave me chills when she said, ” I did it the other way using the distributive property.” The she explained the process flawlessly! I couldn’t have been more proud when she finished. I gave her a big smile and said, ” I love it!” She smiled back because she knew she had nailed it. I would love to hear what you think. Please leave comments below!