Lesson 7

Workshop: Large Numbers

Est. Class Sessions: 1–2

Daily Practice and Problems

Teacher Notes
X

TIMS Task

  1. 17 is the only prime number. Factors for 51 are 1, 3, 17, and 51.
    Factors for 42 are 1, 2, 3, 6, 7, 14, 21 and 42.
  2. Factor trees can vary.
    72 = 2 × 2 × 2 × 3 × 3 or
    72 = 23 × 32

X. Primes and Factors

  1. Which of the following are prime numbers? Explain.
    1. 17
    2. 51
    3. 42
  1. Use a factor tree to factor 72 into primes. Write a number sentence to show your answer.