Multiplication Fact Building With Dice
Lesson 6 of 6
Objective: SWBAT build multiplication facts using models.
Reviewing skills and multiplication models with a manipulative the students have already learned to use as strategies opens this lesson. The purpose of the lesson is to practice fact fluency with multiplication. The students build concrete models with manipulatives which include two sided (red and yellow) counters, unifix cubes, or small chips.
To practice the models, I ask the students to build samples of groups, and items inside of groups. They choose how many groups and how many items (within the guidelines of the Common Core standards of facts to 100). Students then review in the same manner with drawing arrays.
The students practice drawing two models for each type of diagram. This was an appropriate review for my students at this time, and I suggest you modify the task based on student progress with multiplication during the year. Earlier in the year, I would only have the students practice one type of model with a manipulative, or a diagram drawn on a whiteboard with more examples. Later in the school year, I would challenge the students to find the product first, and then draw the diagram to provide evidence and reasoning.
Model Using Dice
To model using the dice for this lesson, we review our math activity expectations. These include rolling the dice within a confined area. One of my students created a reminder, and it has become the term used in our classroom. The students are to roll the dice into their other hand, which he described, "roll them into your other hand like a hockey net." So, the first rule of using dice is that you shoot the dice into the hockey net.
The second guideline is, accidents happen but not each time. My students usually sit on the floor to use dice, and since it is a carpeted room, this does muffle the noise of the room and reduces the chance of dice rolling through the room.
The third guideline is, shake, shake, shake, roll. This creates unpredictable numbers for when they are completing activities needing a specific number.
The last guideline is, dice up in the air above their heads is not an accident. This last guideline was established as a result of (unfortunate) experience.
I have ten sided dice to use for this task, and playing cards (number cards could be used for this lesson also). Kings, queens, and jacks are removed from a deck of playing cards for numbers 1-10. I model the activity, rolling two dice and writing the multiplication sentence this action creates. For example 3 x 5 = ___ or 5 x 3 = ___ is written on the paper. I use blank paper or notebook paper to record the number sentences and models. Then I demonstrate how I use this fact to draw the model, and record the product. I encourage the students to work quickly to emphasize the goal of fluency with this task.
Try It On Your Own
Students work with partners in this task, and each partner rolls one dice. Part of the game is for them to challenge (politely) each other to solve quickly and then compare their products. When it is needed, the students may put a shield between each other to create more of a game format if needed. Other students benefit from problem solving together to support each other.
During this activity two of the students roll 9 x 9, and try to come up with a strategy to solve it mentally. I encourage and challenge them to think through different facts and strategies they already know, including skip counting to assist them with this fact. The reasoning of these students is still developing, but they are beginning to see patterns and relationships, a step to using related facts to find the product.
I ask the students to share with the class one of the strategies they use, besides using a model, to solve a multiplication sentence. I decide that this was a more appropriate close than to discuss the actual work because during the lesson I observe many of the students using skip counting and chants they had learned in second grade for skip counting. I believe sharing these strategies is important so that students can learn from each other.
I have the students turn in their recording sheet for my use as an informative assessment to check their understanding.