Lesson 10

Multiplying Fractions by a Whole

Est. Class Sessions: 2

Daily Practice and Problems

Teacher Notes
X

TIMS Task

Refer students to the Multiplication Strategies Menu for Larger Numbers in the Student Guide Reference section.

Answers will vary. One possible response using mental math is given for each.

  1. 300 × 7 = 2100
  2. 2 × 150 = 300; 7 × 300 = 2100
  3. 1000 × 6 = 6000; 6 × 2 = 12; 6000 − 12 = 5988
  4. Thinking money: 27 is like one quarter plus 2 cents.
    8 quarters is 8 × 25 = 200; 8 × 2 = 16; 800 + 16 = 816
  5. 860 × 10 = 8600; 8600 ÷ 2 = 4300
  6. Double 32 is 64, then double 64 to get 128.

JJ. Mental Math

Which problems below can you solve using mental math? Which ones can you solve with a few quick notes? For which ones do you prefer to use a paper-and-pencil method? Be ready to show or tell how you solved each problem.

  1. 300 × 7 =
  2. 150 × 7 × 2 =
  3. 998 × 6 =
  4. 27 × 8 =
  5. 860 × 5 =
  6. 4 × 32 =