A rational number (or fraction) is represented as a ratio between two integers, a and b, and has the form \({a \over b}\) where a is the numerator and b is the denominator. An improper fraction (\({5 \over 3} \)) has a numerator with a greater absolute value than the denominator and can be converted into a mixed number (\(1 {2 \over 3} \)) which has a whole number part and a fractional part.

A number in scientific notation has the format 0.000 x 10^exponent. To convert to scientific notation, move the decimal point to the right or the left until the number is a decimal between 1 and 10. The exponent of the 10 is the number of places you moved the decimal point and is positive if you moved the decimal point to the left and negative if you moved it to the right:

1,777,000 in scientific notation is 1.777 x 10⁶

To find the average of these 4 numbers add them together then divide by 4:

\( \frac{17 + 11 + 18 + 10}{4} \) = \( \frac{56}{4} \) = 14

To subtract these radicals together their radicands must be the same:

3\( \sqrt{75} \) - 7\( \sqrt{3} \)
3\( \sqrt{25 \times 3} \) - 7\( \sqrt{3} \)
3\( \sqrt{5^2 \times 3} \) - 7\( \sqrt{3} \)
(3)(5)\( \sqrt{3} \) - 7\( \sqrt{3} \)
15\( \sqrt{3} \) - 7\( \sqrt{3} \)

Now that the radicands are identical, you can subtract them:

If 30% of the town's 40,000 voters cast ballots the number of votes cast is:

(\( \frac{30}{100} \)) x 40,000 = \( \frac{1,200,000}{100} \) = 12,000

The mayor got 61% of the votes cast which is:

(\( \frac{61}{100} \)) x 12,000 = \( \frac{732,000}{100} \) = 7,320 votes.