How to find the part from the whole with percentage - SSAT Middle Level Quantitative

The first thing to do is to determine what two numbers multiply to give you 12.

1 and 12

2 and 6

3 and 4

Now find the difference between each of those pairs.

The difference could be 1, 4, or 11. Only 4 is an answer choice.

The storewide sale discounts the shirt by 50%:

Susan also has the 10% off coupon, so she's really paying 90% of the cost of the shirt:

To calculate the tax, multiply 8.5%. or, equivalently, 0.085, by $139.34, rounding to the nearest cent:

Add the tax to the price before tax:

The amount paid will be $151.18.

Multiply the price of the groceries before tax - $154.92 - by the decimal equivalent of 9% , which is 0.09. Round this tax to the nearest hundredth (cents), then add to the price of the groceries.

Tax:

Price after tax:

Taking 250% of a number is the same as multiplying that number by 2.5. We therefore take the product:

of the voters were registered as Republicans, so the rest - - were not. Therefore, we want to calculate of , or, equivalently,

which, to the nearest whole number, rounds to voters

One way to go about solving this problem is to convert the percent into a decimal and multiply your whole number by that in order to get your answer. When converting a percent into a decimal, move the decimal point two spaces to the left:

30% = 0.30

Then, multiply this number times 150:

Your answer is .

One way to figure out what number is a percentage of a larger number is to convert the percent into a decimal and multiply it by the whole number. Since is equal to , multiply this by .

is your answer.

Rewrite as a decimal by writing with a decimal point, then shifting it two spaces left:

Multiply this by :

We can solve for with the algebraic equation:

We can then calculate of :

We can convert to or . We can then calculate .

Taking 8,000%, as a decimal, is equivalent to multiplying it by , so 8,000% of 9,000 is equivalent to

.

Taking 3.33% percent of a number is the same as multiplying it by 0.0333, so 3.33% percent of 3.33 is equal to

.

of can be rewritten as

of is equal to:

Cross-cancel:

220% of a number is 2.2 multiplied by that number, so 220% of 0.00022 is equal to

.

In order to convert numbers to a percent, it is easiest to set up a ratio.

We know that percent is just per-cent or per-100, another way to write this is to divide the number by 100.

We would set up the ratio below with x being the number we are looking for:

Now we cross multiply 25 times x and 12 times 100 to get:

Dividing both sides by 25 will give us the percent.

On the left side the 25's will cancel to give us x, on the right side we may need to do some long division to eventually find that 1200/25 = 48.

One way to solve this problem is to use cross multiplication.

So in order to determine the number of green birds, set this proportion equal to.

Therefore,

Cross multiply to get

. Now divide both sides of the equation by 100 to get

A faster way to solve this problem is to recognize that 100 and 1000 differ by only one decimal place (1000 has an extra zero). Therefore, in order to determine 68% of 1000, simply add an extra zero to 68 and you have 680 birds.

First, we need to determine the percentage of snacks that are unhealthy. To do this, we subtract

Therefore, 30% of snacks are unhealthy.

The quick estimation method allows us to compute this problem quickly and save time on later questions. To begin, we need to determine 10% of the total amount of snacks. In order to find 10% of a number, simply move the decimal point one place to the left. So, 10% of 500 snacks is 50 snacks.

We want to determine how many snacks constitute 30% of the total amount of snacks. 30% is 3 times 10% so all we need to do is multiply 10% (50 snacks) by 3. Therefore,

are unhealthy.