Adding and
Subtracting
By: Jenny Erickson
Adding in Scientific Notation
and
Subtracting in Scientific Notation
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.

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.

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.)

Adding With the Same Exponent
(3.45 x 103) + (6.11 x 103)
 3.45 + 6.11 = 9.56

 9.56
x 103
Adding With Different
Exponents
(4.12 x 106) + (3.94 x 104)
 (412 x 104) + (3.94 x 104)
 412 + 3.94 = 415.94
 415.94 x 104


Express in proper form: 4.15
x 106
Now it’s your turn.

Use the link below to practice adding
numbers in scientific notation.

Adding Numbers in Scientific Notation
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).

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.)

Subtracting With the Same
Exponent
(8.96 x 107) – (3.41 x 107)
 8.96 – 3.41 = 5.55

 5.55
x 107
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
Now it’s your turn.

Use the link below to practice
subtracting numbers in scientific
notation.

Subtracting Numbers in Scientific
Notation
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
