Math Semester Final

How To: Ratios & Unit Rates

What Is a Rate? A rate is a comparison of two quantities that have different units. An example is 90 miles/3 hours, which is read as 90 miles per 3 hours.

How To: Scale Factor

What Is Scale Factor? Scale factor is the ratio of the length of the scale drawing to the corresponding length of the original object.

What Is Dimensional Analysis? Dimensional analysis is used to convert units. It's the process of analyzing units to decide which conversion factor to use. It's used by multiplying units by conversion factors, rates equal to 1.

How To: Solve Proportions

The Solution The first step to solving proportions is cross multiplying. For example, we are told to solve the proportion 13/3 = x/9. We cross multiply 13 •9 and 3 • x. Remember, the equal sign does not go away, so don't forget about it! The equation is now 3x = 117. We need to isolate the variable so we do 3x ÷ 3, which is x, and 117 ÷ 3, which equals 39. We now know that x = 39. Practice Time

How To: Check for Proportions

What Are Proportions? Proportions are 2 ratios that are equal.

How To: Pythagorean Theorem

What Is Pythagorean Theorem? Pythagorean Theorem is an equation discovered by a man named Pythagoras. It can be used to determine whether or not a triangle is a right triangle and find missing lengths of a triangle. The equation is: Parts of a Triangle

How To: Estimate Square Roots

What Is a Square Root and a Radicand? A square root is a number that when multiplied by itself, results in its original number. For example, the square root of 16 is 4 because 4 • 4 = 16.