After working for a few weeks on different multiplication strategies, we started working on finding the missing factor. This was my first year teaching this skill and to be honest I wasn’t exactly sure where they’d take it. I first posed a problem to the group in a number talk and let them share out their strategies while I documented them on the board. I was majorly impressed by what they came up with. Because of their ability to think flexibly with numbers and their variety of strategies and solid understanding of multiplication – they did amazing!
Here are a few examples of strategies used for the problem ___ x 4 = 20. I told them that in addition to writing the answer, they also had to prove it.
This student made an array to show that the 4 rows to get to 20 would have 4 in each row.
This student used skip counting to get to 20. They skip counted by 4 and realized it took them 5 times to get to 20.
This student used a number line to jump up by 4 each time and see how many times they had to do that to get to 20.
This student used a combination of skip counting, but also had it clearly marked after so you could see where they got 5 as their answer from.
After working on this during whole group instruction for a day or two, students participated in “Find the Missing Factor Around the Room” This product is now up in my TPT store. I love Around the Room activities because it gives kids practice on a certain skill, but it’s not just a worksheet. Students are able to go in any order they want and they’re up and moving.
Here’s an example problem and the recording sheet:
Check it out in my TPT store here. Finding the Missing Factor Around the Room includes 16 cards, a recording sheet, and answer key.