Percentages are like fractions and decimals. They can be used to describe the proportion of a whole and its parts. Percentage is a term from a Latin word which means “out of one hundred”. We may therefore consider percentage as part of a whole. That whole or total is the base. The number with the percent (%) symbol is the rate.​

The P is on top because it represents the idea that it should be divided by either R or B, depending on what are given. The B and R are at the bottom to suggest that both can be multiplied.​

Thus,

P = R multiplied by B

R = P divided by B

B = P divided by R

Example 1

Emmie is excited to go to the supermarket with her mother. Their shopping list includes condensed milk, full-cream milk, Graham crackers and mangoes. The Graham crackers costs P 60.00 per pack, but is being sold at 10% discount! How much will she save per pack if she buys the Graham crackers?

From the problem above, we have learned that 10% of P60 is P6. Note that 10% is the rate (the expression with the % symbol). The percentage (part of the whole or part of P60.00) is P6. The base (whole or total) is P 60.

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Alternatively, we may write a proportion and solve for the unknown (n). n out of 60 = 10 out of 100

n:60 = 10:100

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​By the cross-product rule, we have the following

​100 × n = 60 × 10

100n = 600

100n = 600

100 100

n = 6​

Therefore, P 6 will be deducted from the original price of the Graham crackers. It will also be the amount that Emmie will save. Using proportion or bar model above is also useful in solving the problem.​

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