1. Adding and Subtracting
By: Jenny Erickson

2. Adding in Scientific Notation and Subtracting in Scientific Notation

3. Adding and Subtracting…
The important thing to remember about adding or subtracting is that the exponents must be the same!
If the exponents are not the same then it is necessary to change one of the numbers so that both numbers have the same exponential value.

4. Adding… The general format for adding is as follows…
(N x 10x) + (M x 10x) = (N + M) x 10x
The first step, if necessary, is to change one of the numbers so that both numbers have the same exponential value.

5. Adding…
Secondly, add the N and M numbers together and express as an answer.
The final step is to multiply the result by the 10x.
(It may be necessary to put the resulting answer into proper scientific notation.)

6. Adding With the Same Exponent
(3.45 x 103) + (6.11 x 103)
= 9.56
9.56 x 103

7. Adding With Different Exponents
(4.12 x 106) + (3.94 x 104)
(412 x 104) + (3.94 x 104) =
x 104
Express in proper form: 4.15 x 106

8. Now it’s your turn.
Use the link below to practice adding numbers in scientific notation.
Adding Numbers in Scientific Notation

9. Subtracting… The general form for subtracting is as follows…
(N x 10x) – (M x 10x) = (N – M) x 10x
The first step, if necessary is to change one of the numbers so that both numbers have the same exponential value. (Just like adding).

10. Subtracting…
Secondly, subtract the M number from the N number and express as an answer.
The final step is to multiply the result by the 10x.
(It may be necessary to put the resulting answer into proper scientific notation.)

11. Subtracting With the Same Exponent
(8.96 x 107) – (3.41 x 107)
8.96 – 3.41 = 5.55
5.55 x 107

12. Subtracting With Different Exponents
(4.23 x 103) – (9.56 x 102)
(42.3 x 102) – (9.56 x 102)
42.3 – 9.56 = 32.74
32.74 x 102
Express in proper form: 3.27 x 103

13. Now it’s your turn.
Use the link below to practice subtracting numbers in scientific notation.
Subtracting Numbers in Scientific Notation

14. Quiz Time!!!
Below is a set of links for a quiz on adding and subtracting numbers in scientific notation, and there is a link to get the answers to the quiz.
Adding and Subtracting Quiz
Answers to Quiz