Adding and subtracting in scientific notation

The  exercise appears under the 8th grade (U.S.) Math Mission. This exercise practices adding and subtracting in scientific notation.

Types of Problems
There is one type of problem in this exercise:
 * 1. Express your answer in scientific notation.: This problem involves numbers with decimals and exponents. The student is asked to express the answer in scientific notation.

Strategies
Knowledge of scientific notation is essential to ensure success on this exercise.
 * 1. A number is in scientific notation if it is written in the form of $$a\times 10^n$$ where n is an integer and a is a number such that $$ 1\leq a <10 $$.
 * 2. To make a number into scientific notation, move the decimal to the spot immediately to the right of the first non-zero digit reading from the left. This is a. The number of spots moved is n if you moved it left, and -n if you moved it right.

Real-life Applications

 * 1. Scientific notation is often used to describe far distances.