Which Three Go Together

10 min

Narrative

This Warm-up prompts students to compare four strings of numbers. To identify which 3 go together, students may use what they know about properties and kinds of numbers—factors and multiples, odd and even numbers, numbers in base-ten, and so on. It gives students a reason to use language precisely (MP6). It gives the teacher an opportunity to hear how students use terminology to talk about the characteristics of the items in comparison to each other.

In the discussion, it is important to talk about what the writer had to pay attention to when they designed this activity. This understanding will prepare students for a series of design activities that lead to an opportunity to create their own Which Three Go Together?

Launch

  • Groups of 2
  • Display the numbers.
  • “Pick 3 number series that go together. Be ready to share why they go together.”
  • 1 minute: quiet think time
Teacher Instructions
  • “Discuss your thinking with your partner.”
  • 2–3 minutes: partner discussion
  • Share and record responses.

Student Task

Which 3 go together?

  1. 0, 4, 8, 12, 16
  2. 3, 6, 9, 12, 15
  3. 5, 105, 205, 305, 405
  4. 6, 60, 600, 6,000, 60,000

Sample Response

Sample response:

A, B, and C go together because:

  • The numbers increase by the same amount each time.

A, B, and D go together because:

  • They have a two-digit number.
  • They have even numbers.

A, C, and D go together because:

  • They are either all odd or all even numbers.

B, C, and D go together because:

  • They have a multiple of 5.
Activity Synthesis (Teacher Notes)
  • “What did you look for when deciding which three number series go together, or when finding a reason why three go together?” (numbers with 1–5 digits, factors and multiples, odd and even numbers, patterns, how the numbers increased)
  • Record and display responses for all to see.
  • “What did the writer of this activity have to pay attention to when they designed this activity?” (The writer looked for those same reasons but needed to make sure that all groups had at least three features in common. Also, each item is missing a feature that the other three items have.)
Standards
Building On
  • 4.OA.B·Gain familiarity with factors and multiples.
  • 4.OA.B·Gain familiarity with factors and multiples.
  • 4.OA.C·Generate and analyze patterns.
  • 4.OA.C·Generate and analyze patterns.

20 min

15 min

15 min