**Basic mathematics**- Solve mathematical problems requiring simple addition, subtraction, multiplication, division, and raising numbers to exponential powers. Round to the appropriate number of significant digits, calculate percentages, read graphs, and use simple geometric definitions and formulas.- Basic mathematics Review skills in addition, subtraction, multiplication, division, and percent.
- Rounding Numbers Rounding means making a number simpler but keeping its value close to what it was.
- Percentages (%) One percent (1%) means 1 per 100.
- Ratios A ratio says how much of one thing there is compared to another thing.
- Reciprocal of a Fraction To get the reciprocal of a fraction, just turn it upside down.
- Exponential powers The exponent of a number says how many times to use the number in a multiplication.
- Scientific Notation Scientific notation is the way that scientists easily handle very large numbers or very small numbers. For example, instead of writing 0.0000000056, we write 5.6 x 10
^{-9}. We can think of 5.6 x 10^{-9}as the product of two numbers: 5.6 (the digit term) and 10^{-9}(the exponential term). - How to read graphs Graphs can be used to visually represent the relationship of data.
- Geometry Index Geometry is all about shapes and their properties. Geometry can be divided into Plane Geometry and Solid Geometry.

**Basic metric units and conversions**- Perform conversions to and from basic metric (SI) units.- Metric Unit Converter To convert units in the metric system, identify the unit that you have, the unit that you want to convert to, and then count the number of units between them.
- Converting within the Metric System While knowing the different units used in the metric system is important, the real purpose behind learning the metric system is for you to be able to use these measurement units to calculate the size, mass, or volume of different objects.
- Metric units of mass review (g and kg) Mass is used to measure the weight of an object. For example, you are measuring the mass of your body when you step on to a scale.
- Metric units of length review (mm, cm, m, & km) Review the size of millimeters, centimeters, meters, and kilometers and how to convert between them. Then, try some practice problems.
- Converting units of time review (seconds, minutes, & hours) Review the size of seconds, minutes, and hours and how to convert between them. Then, try some practice problems.
- Essentials of the SI: Base & Derived Units The SI is founded on seven SI base units for seven base quantities assumed to be mutually independent.

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