20% of a number is 8. Find the number and check.
40
Whole = 8 ÷ 1/5 = 40. Check 20% × 40 = 8.
Day 057Finding the Whole
Standards 6.RP.A.3c
LEARNING TARGET
I can find the whole when a part and percent are known.
01 · LEARN
Build the idea
Write part = decimal rate × whole. Divide the part by the decimal rate to find the whole. Check by taking the stated percent of your answer.
125% of a number is 50. Find the number and check.
40
Whole = 50 ÷ 5/4 = 40. Check 125% × 40 = 50.
02 · PRACTICE
Your turn
Work in order. Start with the foundations, then build toward explanation and application.
20% of a number is 8. Find the number and check.
10% of a number is 22. Find the number and check.
50% of a number is 110. Find the number and check.
30% of a number is 60. Find the number and check.
15% of a number is 30. Find the number and check.
25% of a number is 55. Find the number and check.
9 students are 15% of a school’s enrollment. Find the enrollment.
18 students are 30% of a school’s enrollment. Find the enrollment.
12 students are 30% of a school’s enrollment. Find the enrollment.
120 students are 60% of a school’s enrollment. Find the enrollment.
03 · CHECK
Answers and reasoning
Reveal the teacher answer key
- 40
Whole = 8 ÷ 1/5 = 40. Check 20% × 40 = 8.
- 220
Whole = 22 ÷ 1/10 = 220. Check 10% × 220 = 22.
- 220
Whole = 110 ÷ 1/2 = 220. Check 50% × 220 = 110.
- 200
Whole = 60 ÷ 3/10 = 200. Check 30% × 200 = 60.
- 200
Whole = 30 ÷ 3/20 = 200. Check 15% × 200 = 30.
- 220
Whole = 55 ÷ 1/4 = 220. Check 25% × 220 = 55.
- 60
Whole = 9 ÷ 3/20 = 60. Check 15% × 60 = 9.
- 60
Whole = 18 ÷ 3/10 = 60. Check 30% × 60 = 18.
- 40
Whole = 12 ÷ 3/10 = 40. Check 30% × 40 = 12.
- 200
Whole = 120 ÷ 3/5 = 200. Check 60% × 200 = 120.