## Geometry: Hair Cutting Angles

Math is used in cosmetology hair cutting angles daily. For example, a cosmetologist cutting layers into a haircut must use a variety of angles to create the desired layered look. If hair is to be cut with short layers, the cosmetologist has to decide whether to cut layers at a 45-degree angle or a 90-degree angle. Layered hairstyles, along with men's cuts, incorporate a lot of math when it comes to math used in cosmetology.

## Addition and Multiplication: Color Measurements

Color and bleach must be measured properly to achieve the result the client wants. Hair color and color developer must be mixed at the exact ratio that's needed. Hair color and developer is often mixed at a 2 to 1 ratio, meaning two parts of color to one part of developer. The cosmetologist must use math to decide how much developer and color to use. For example, if the cosmetologist is mixing 2 oz. color, she must use 1 oz. developer, equaling 3 oz. total.

## Division: Sectioning Hair

For almost any hair service, the cosmetologist must section hair into parts. Typically, every service begins by sectioning hair into four parts. Then there are a number of subsections that are divided accordingly.

## Finance: Income vs. Expenses

A cosmetologist doesn't just have to consider how much money she's making with service prices. She also must factor in her expenses--such as booth rent, commission payments and product costs. These all must be considered in determining what she's paid.