When I was young and learned division, there was one way to do it, long division. Then, common core came around and as a teacher, I was introduced to sooo many division strategies. Of course, some I like better than others, just like my students will. My favorite new division strategy is long division box method.
What Makes Long Division so Hard?
My students have always struggled with long division. It has never been one of my favorite things to teach. The biggest problem that I always found with long division is that once students would bring down the next number, they didn't know what to do next. Even if they knew the step was divide, what are they dividing into? That's where they always got confused. That's what I like about the box method. It clears up that confusion for them, making it much easier to go through the long division steps.
Let's Start with the Steps to Long Division
The steps for the box method are the same as traditional long division.
When I first started teaching (a long time ago), the steps I first used were divide, multiply, subtract, and bring down. I taught my students to use dad, mom, sister, and brother to help them remember the steps.
The problem with those steps is that they're missing an important step which is to check (is your number after subtracting smaller than your divisor?). By checking, students know immediately if the number they used for the dividing step was too small. So I started using dad, mom, sister, cat, and brother. Not the best mnemonic device.
A number of years ago I learned a new saying to help students remember the steps. "Does McDonald's Sell Cheese Burgers" - divide, multiply, subtract, check, bring down.
I have a free poster with the steps to long division to help students remember the steps.
How do you do the Long Division Box Method?
The problem is set up very similar to regular long division, the difference is that you put the numbers of the dividend into separate boxes (I also have the students label the place names of each of the boxes). The students divide the divisor into the largest digit of the dividend just like regular long division and go through the same steps. The biggest difference is when you get to the step where students would normally bring down. Instead, they take the number they got from subtracting and bring it over to the next box, making a new number. Now, there's only one number in the new box, making it easy for students to know what they are now dividing into.
The video below shows how to do a problem using the box method. It's much easier to show than explain.
I use this Long Division Box Method Unit to teach it to my students. It breaks down the steps, and scaffolds from smaller to larger problems.
Advantages of the Long Division Box Method
1. As the dividends get bigger, students that aren't always neat in their writing don't have the difficulty of keeping everything lined up.
2. When the student brings over, they now easily know what number they are going to divide the divisor into.
3. If a student has an error, it is easier to point out where they made the error. For example, you could let them know that they made a mistake in their tens place.
One last point is that it's important for students to know their multiplication facts when they get to these larger math problems. I have some fun activities that I use in my classroom to help students practice those facts.
Have you taught the division box method in your class? If not, give it a try and let me know how it goes.
~Jill
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