Begin by creating “flash cards” with the numbers 1-9 written on them. You will want a very large bowl with these. Mix them up thoroughly. Now divide your classroom into sets of partners or groups with three students each. Each group will come up to the bowl and pick 5 cards. The luck of the draw will impact how well a group can do!
Let’s say one group has picked: 2, 3, 7, 8, 9
You will also give each group the number “0.”
The goal is to create numbers by using these digits, that can be divisible by any of the numbers 2, 3, 5, through 10.
The students can use the numbers over and over, but they can’t use the same number more than once in a completed number. For example, for this group, they can have:
280, but not 2880, or 2080
280 is divisible by 2, 4, 5, 7, 8, and 10
Give them a time limit to create these numbers and list the numbers that they are divisible by. The group with the most numbers using their digits properly wins. However, they must document all the divisibility numbers in their lists. If they miss one, they are disqualified. For example, if a group creates 280, but they miss 8 as a factor, they would be disqualified!
Now that students have played “Digit Widgets” in class it’s time to add a new and more challenging twist.
Follow the same process as before. Break your class up into partners or groups of 3 (ha ha…if you have a class number that’s divisible by 3!).
Have the groups come up to their number bowl and pick out 5 numbers.
Group A has picked 1, 3, 5, 5, 6
Group B has picked 2, 4, 7, 9, 9
Now give them the wild card “0” and tell them that unlike Digit Widgets Part 1, they can now use the “0” card as many times as they like.
Remind them that they have to list all the numbers from 1-10 that the number they create is divisible by.
For example, Group A can create the number 55000, but they can’t create the number 5550 because it uses one more 5 than they have.
Group B can create the numbers 204, 2040, and 20400 but they can’t create 2440 since it uses two digits with “4.”
The group that ends up with the most created numbers with all the proper factors wins. If they miss a factor they are disqualified!
Since they are working with large numbers, you can give them the use of a calculator, but it may slow them down instead of speed them up!