Lesson 3 Is it Odd or Even?

    • Let’s explain why the number of objects in a group is even or odd.

Warm-up Choral Count: Skip Count by 2

Count by 2, starting at 2.

What patterns do you see?

Activity 1 Color by Number

Han wants to color a design with the same number of yellow and blue shapes.

A
10 circles arranged in oval-like design.
B
9 circles. 8 arranged in a circle with 1 circle in the middle.
C
Circles. 15 circles arranged in a circle with 3 circles in the middle.
D
12 circles in the shape of a circle with 4 circles in the middle.

  1. Which designs could Han choose? Show your thinking using diagrams, symbols, or other representations. Use counters if it helps.

  2. Draw a circle design that would work for Han and a circle design that would not work.

  3. Priya drew a design that has 6 circles, 3 triangles, and 3 squares. Would Han be able to color it the way he wants? Show your thinking using diagrams, symbols, or other representations. Use counters if it helps.

Activity 2 Card Sort: Even or Odd

  1. Sort your cards into a group that shows an even number and a group that shows an odd number.

    Explain your thinking to your partner.

  2. Find 3 cards that show the same number. Explain to your partner how each card shows whether the number is even or odd in a different way.

Practice Problem

Problem 1

For each image, decide whether the number of dots is even or odd. Explain or show your reasoning.

  1. Groups of dots. Two rows. First row, 7 yellow dots. Second row, 6 red dots.
  2. Two groups of 7 red dots.
  3. 10 red dots.