Math Coach Lesson index ↗
Unit 03 · Ratios and MeasurementLesson

Day 032Parts and the Whole

LearnClassworkAnswer keyPDF packet ↗
Standards 6.RP.A.1
LEARNING TARGET

I can distinguish part-to-part and part-to-whole comparisons.

01 · LEARN

Build the idea

For a:b, the total is a+b equal parts. The first part is a/(a+b) of the total; a/b compares it to the second part. Write labels before choosing the denominator.

WORKED EXAMPLE 1

A collection has 25 green and 10 yellow counters. Write the fraction that is green.

5/7

Total = 35; green fraction = 25/35 = 5/7.

WORKED EXAMPLE 2

A collection has 12 green and 6 yellow counters. Write the fraction that is green and the green-to-yellow ratio in simplest form. Explain the different denominators.

2/3; 2 or 2:1; the whole includes both colors

Total = 18; green fraction = 12/18 = 2/3.

02 · PRACTICE

Your turn

Work in order. Start with the foundations, then build toward explanation and application.

  1. A collection has 25 green and 15 yellow counters. Write the fraction that is green.

  2. A collection has 8 green and 10 yellow counters. Write the fraction that is green.

  3. A collection has 12 green and 18 yellow counters. Write the fraction that is green.

  4. A collection has 10 green and 14 yellow counters. Write the fraction that is green.

  5. A collection has 12 green and 20 yellow counters. Write the fraction that is green.

  6. A collection has 35 green and 30 yellow counters. Write the fraction that is green.

  7. A collection has 15 green and 20 yellow counters. Write the fraction that is green and the green-to-yellow ratio in simplest form. Explain the different denominators.

  8. A collection has 15 green and 21 yellow counters. Write the fraction that is green and the green-to-yellow ratio in simplest form. Explain the different denominators.

  9. A collection has 20 green and 35 yellow counters. Write the fraction that is green and the green-to-yellow ratio in simplest form. Explain the different denominators.

  10. A collection has 18 green and 9 yellow counters. Write the fraction that is green and the green-to-yellow ratio in simplest form. Explain the different denominators.

03 · CHECK

Answers and reasoning

Reveal the teacher answer key
  1. 5/8

    Total = 40; green fraction = 25/40 = 5/8.

  2. 4/9

    Total = 18; green fraction = 8/18 = 4/9.

  3. 2/5

    Total = 30; green fraction = 12/30 = 2/5.

  4. 5/12

    Total = 24; green fraction = 10/24 = 5/12.

  5. 3/8

    Total = 32; green fraction = 12/32 = 3/8.

  6. 7/13

    Total = 65; green fraction = 35/65 = 7/13.

  7. 3/7; 3/4 or 3:4; the whole includes both colors

    Total = 35; green fraction = 15/35 = 3/7.

  8. 5/12; 5/7 or 5:7; the whole includes both colors

    Total = 36; green fraction = 15/36 = 5/12.

  9. 4/11; 4/7 or 4:7; the whole includes both colors

    Total = 55; green fraction = 20/55 = 4/11.

  10. 2/3; 2 or 2:1; the whole includes both colors

    Total = 27; green fraction = 18/27 = 2/3.

← Lesson indexBack to top ↑Day 033 →