Base-Ten Diagrams to Represent Division

10 min

Narrative

This Warm-up prompts students to carefully analyze and compare features of base-ten diagrams, looking not only at the number and types of shapes in each diagram, but also the value each diagram represents. Students have a reason to use language precisely (MP6) as they recall what they know about representations of numbers in base-ten. The activity also enables the teacher to hear how students talk about these representations.

The analysis prepares students for the activities in the lesson, in which they use base-ten diagrams to find whole-number quotients.

Launch

  • Groups of 2
  • Display image.
  • “Pick 3 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
  • Record responses.

Student Task

Which 3 go together?

A
base ten diagram. 1 hundred, 1 ten, 1 one.

B
base ten diagram. 10 tens, 1 one.

C
base ten diagram. 1 hundred, 11 ones.

D
base ten diagram. 3 groups of 3 tens, 7 ones.

Sample Response

Sample responses:

  • A, B, and C go together because they have a column with just a single square.
  • A, B, and D go together because they have tens.
  • A, C, and D go together because they show 111.
  • B, C, and D go together because they have 10 blocks.
Activity Synthesis (Teacher Notes)
  • “How is it that A and C both show 111?” (If a small square represents 1, then a rectangle is 10 and a large square is 100. In A: 100+10+1=111100 + 10 + 1 = 111. In C: 100+11=111100 + 11 = 111.)
  • “How do we know that D also shows 111?” (Each group in D represents (3×10)(3 \times 10) + 7 or 37. Three groups of 37 makes 111.)
  • “Suppose we don’t know what a small square represents except that it represents the same value in all diagrams. Can we tell if C and D represent the same value? How?” (Yes. We know that 10 small squares make 1 rectangle and 10 rectangles make 1 large square. In D, we’d have 21 small squares and 9 rectangles. Trading 10 small squares for a rectangle gives 10 rectangles and 11 small squares, which is equal to 1 large square and 11 small squares.)
Standards
Building Toward
  • 4.NBT.6·Find whole-number quotients and remainders with up to four-digit dividends and one-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.
  • 4.NBT.B.6·Find whole-number quotients and remainders with up to four-digit dividends and one-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

15 min

20 min