Percentages can be one of the most confusing mathematical concepts for children, and even adults, to master. Yet, an understanding of percents is critical in everyday life. The following intuitive approach focuses on the true meaning of percents as opposed to methods that are based on rote memorization of formulas. You'll find that this method, which uses mental math, makes percents less intimidating and even fun!
When calculating percents, the first step is to realize that “per cent” can be defined as “for each 100.” Using this concept, you can easily solve percent problems. For example, 6% of 300 is 18, because 6% means “count 6 for each 100.” Therefore, since 300 = 100 + 100 + 100, count 6 three times, once for each 100 (6 + 6 + 6 = 18).
Take this example a step further by solving for 6% of 350. You arrive at 21 by again counting 6 for each 100; however, you now need to account for the additional 50. Since 50 is ½ of 100, you need to add ½ of 6, which is 3. Therefore, your answer of 21 is calculated by adding 6 + 6 + 6 + 3 = 21.
Extending the original example even further, you can find 6% of 325. Since 25 is ¼ of 100, you need to add ¼ of 6, which is 1 ½. Calculating ¼ of a number can be a bit intimidating, but finding ¼ of a number can often be done using mental math as well. Simply divide your number in half, two times. For example, ½ of 6 = 3, and ½ of 3 = 1 ½. Therefore, 6% of 325 is 6 + 6 + 6 + 1 ½ = 19 ½.
You can test your ability, as well as your child’s ability, to calculate percents using mental math by completing the following problems. Answers can be found at the bottom of this article.
(1) 7% of 300
(2) 6% of 500
(3) 15% of 300
(4) 25% of 400
(5) 20% of 500
(6) 6 ½% of 200
(7) 8% of 50
(8) 7% of 50
(9) 12% of 250
(10) 8% of 225
Answers:
(1) 21
(2) 30
(3) 45
(4) 100
(5) 100
(6) 13
(7) 4
(8) 3 ½
(9) 30
(10) 18
For more math tips, check out Bobby's advice on problem-solving and number sense.
