This is a great way to get your students into groups and assess their number sense, as well as their cooperation skills.

### Preparation:

I whipped up these cards with different types of rational and irrational numbers. They are available for free in our resource library when you sign up for our email list, but you can easily make your own set. I copied the different pages on different colored paper, which made it easy to keep track of which types of numbers each group was working on.

The types of numbers that I had (in order) included:

• Positive whole numbers
• Negative numbers
• Positive and negative decimals
• Fractions
• Mixed numbers
• Improper fractions
• Numbers with exponents
• Square roots
• Irrational numbers, terminating decimals, etc.

Put your students into groups. I put mine into groups of 3, so all of the students had a chance to participate. We were working at small tables, but if you have the space, I’d recommend long tables, or the floor. My students’ number lines ended up becoming curved because of a lack of space (although they thought this was pretty cool).

### Give directions:

Tell your students that the goal is to put the numbers in order from least to greatest. If numbers have the same value, they should go on top of each other so both numbers can be seen (for example, ½ and .5). The shouldn’t tell you that they are finished with a set of cards until ALL of the group members can explain why the numbers are in a particular order. They are allowed to teach and explain to each other.

### Begin the activity:

Give each student the first pack of cards. I actually gave students half a pack at a time. For example, I gave the positive whole numbers, had them check in with me, and then gave them the negative whole numbers. If a group has a number out of order, tell them there is a mistake, but do NOT tell them what the mistake is. This will get the group members to think critically before they come back to have you check their work again.

Groups will complete each set at different times, and some groups will get much further in the process than other groups. This is okay. Make notes as you walk around, observing which groups and students have limited or advanced knowledge of the concepts. I did this activity with a class of 5th, 6th, and 7th graders. Some fifth graders had never even been exposed to negative numbers, but learned the basics from their classmates, giving them excellent background knowledge with no direct instruction from me.