Percents can be one of the most confusing mathematical concepts for children (and yes, 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 will find that this mental math method 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." Applying this concept, one 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 (6 + 6 + 6 = 18).
Taking this example a step further in complexity -- 6% of 350 is 21. We arrive at this answer by again counting 6 for each 100; however, we now need to account for the additional 50. Since 50 is ½ of 100, we need to add ½ of 6, which is 3. Therefore, our answer of 21 is calculated by adding 6 + 6 + 6 + 3 = 21.
Extending our original example even further, we can find 6% of 325. Since 25 is ¼ of 100, we need to add ¼ of 6, which is 1 ½. Calculating ¼ of a number can be a bit intimidating until one realizes that finding ¼ of a number can often be done using mental math as well. One simply needs to remember that you need to 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 + 1½ = 19½.
You can test your ability, as well as your child's ability, to calculate percents using mental math by completing the following 10 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) 6½% of 200
(7) 8% of 50
(8) 7% of 50
(9) 12% of 250
(10) 8% of 225
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Answers:
(1) 21
(2) 30
(3) 45
(4) 100
(5) 100
(6) 13
(7) 4
(8) 3½
(9) 30
(10) 18
