Question

day 21
name:
decimals, percentages, and fractions
before you can calculate sales, discounts, and taxes, youll first need to understand how to use percentages, decimals, and fractions. well review these skills in this section, but if you would like more practice, you may want to consider using the book shown to the right.
converting between decimals and percentages
percentages are used to represent decimals. a percentage is a decimal that is multiplied by 100. this means a decimal is a percentage divided by 100. for example, 0.5 is equal to 50%. another example is that 35% is equal to 0.35.
its not hard to convert between decimals and percentages as long as you know how to multiply and divide by 100. remember, an easy way to do this is to move the decimal point 2 spaces right to multiply and 2 spaces left to divide.
examples:
converting a decimal to a percent:
0.79 = 0.79 = 079. = 79 = 79%
converting a percent to a decimal:
15% = 15 = 15. =.15 = 0.15
problems 1 - 16: convert the decimals to percents.
① 0.12 = ____ % ② 0.95 = __ % ③ 0.03 = __ % ④ 2.04 = ____ %
⑤ 0.01 = ____ % ⑥ 0.6 = __ % ⑦ 5.4 = __ % ⑧ 0.51 = ____ %
⑨ 0.002 = ____ % ⑩ 0.87 = __ % ⑪ 0.049 = __ % ⑫ 0.63 = ____ %
⑬ 4.97 = ____ % ⑭ 0.005 = __ % ⑮ 0.308 = __ % ⑯ 0.992 = ____ %
problems 17 - 32: convert the percentages to decimals.
⑰ 75% = ____ ⑱ 39% = __ ⑲ 318% = __ ⑳ 7% = ____
㉑ 6.4% = ____ ㉒ 102% = __ ㉓ 0.5% = __ ㉔ 20% = ____
㉕ 190% = ____ ㉖ 2.5% = __ ㉗ 3% = __ ㉘ 54% = ____
㉙ 0.8% = ____ ㉚ 249% = __ ㉛ 7.1% = __ ㉜ 709% = ____
© libro studio llc 2022

Explanation:

Step1: Convert decimals to percents

To convert a decimal to a percent, multiply by 100 (move decimal 2 places right).

1. \(0.12\times100 = 12\), so \(0.12 = 12\%\)
2. \(0.95\times100=95\), so \(0.95 = 95\%\)
3. \(0.03\times100 = 3\), so \(0.03=3\%\)
4. \(2.04\times100 = 204\), so \(2.04 = 204\%\)
5. \(0.01\times100 = 1\), so \(0.01 = 1\%\)
6. \(0.6\times100 = 60\), so \(0.6 = 60\%\)
7. \(5.4\times100 = 540\), so \(5.4 = 540\%\)
8. \(0.51\times100 = 51\), so \(0.51 = 51\%\)
9. \(0.002\times100 = 0.2\), so \(0.002 = 0.2\%\)
10. \(0.87\times100 = 87\), so \(0.87 = 87\%\)
11. \(0.049\times100 = 4.9\), so \(0.049 = 4.9\%\)
12. \(0.63\times100 = 63\), so \(0.63 = 63\%\)
13. \(4.97\times100 = 497\), so \(4.97 = 497\%\)
14. \(0.005\times100 = 0.5\), so \(0.005 = 0.5\%\)
15. \(0.308\times100 = 30.8\), so \(0.308 = 30.8\%\)
16. \(0.992\times100 = 99.2\), so \(0.992 = 99.2\%\)

Step2: Convert percents to decimals

To convert a percent to a decimal, divide by 100 (move decimal 2 places left).

1. \(75\%\div100=0.75\)
2. \(39\%\div100 = 0.39\)
3. \(318\%\div100=3.18\)
4. \(7\%\div100 = 0.07\)
5. \(6.4\%\div100=0.064\)
6. \(102\%\div100 = 1.02\)
7. \(0.5\%\div100=0.005\)
8. \(20\%\div100 = 0.2\)
9. \(190\%\div100=1.9\)
10. \(2.5\%\div100 = 0.025\)
11. \(3\%\div100=0.03\)
12. \(54\%\div100 = 0.54\)
13. \(0.8\%\div100=0.008\)
14. \(249\%\div100 = 2.49\)
15. \(7.1\%\div100=0.071\)
16. \(709\%\div100 = 7.09\)

Answer:

1. 12%
2. 95%
3. 3%
4. 204%
5. 1%
6. 60%
7. 540%
8. 51%
9. 0.2%
10. 87%
11. 4.9%
12. 63%
13. 497%
14. 0.5%
15. 30.8%
16. 99.2%
17. 0.75
18. 0.39
19. 3.18
20. 0.07
21. 0.064
22. 1.02
23. 0.005
24. 0.2
25. 1.9
26. 0.025
27. 0.03
28. 0.54
29. 0.008
30. 2.49
31. 0.071
32. 7.09