1. Math for Chemistry Cheat Sheet

2. Scientific Notation
Significant Figures

3. Metric System (SI):
Definitions:
How to study chem:
Calculator Tips:

4. Scientific Notation
What: a short hand method of writing numbers using the powers of 10 (exponents)
*Positive exponents = BIG
*Negative exponents = small
Converting into sci. not.:
Move decimal point after 1st non-zero #
Count the number of times the decimal is moved & use this as the exponent
Examples: = x 106
= x 10-4
Converting out of sci. not.:
Move the decimal point the number of time of the exponent
Examples: 3.25 x 10-5 =
x 104 = 72004
*If there is no decimal point, put it at the end  72 = 72.
Calculations with sci. not.:
Adding/Subtracting:
Convert to same exponents
Add or subtract numbers & keep exponents
Examples: (2.1 x 103) + (3.2 x 103) = (5.3 x 103)
(3.5 x 102) – (4.0 x 101)
(.40 x 102) = (3.1 x 102)
Multiplying:
Multiply numbers & add exponents
Example: (2 x 106) x (3 x 103) = (6 x 109)
Dividing:
Divide numbers & subtract exponents
Example: (4.2 x 107) ÷ (2.1 x 102) = (2 x 105)

5. Significant Figures
Why: in every measurement there are digits that are known & a digit that is estimated or uncertain
What: the digits of a number presented to show accuracy and precision of that measurement
Counting:
If a decimal is in the number , start with the first non-zero number & count all digits until the end
Examples:  5 sig figs  1 sig f.
If no decimal, start with the first non-zero number & count until the last non-zero number
Examples: 202 &  both 3 sig figs
Rounding:
< 5 then round down & ≥5 then round up
Examples: round to 3 sig figs  6.63
round to 3 sig figs  3.47
Calculating answers to correct sig figs.:
Adding or Subtracting:
Determine the least # of decimal places in problem & round to that number of decimal places
Example: g g = g
3 dec 1 dec g
places place
Multiplying or Dividing:
Determine the least # of sig figs in problem & round to that # of sig figs
Example: g ÷ 1.50 mL = g/mL
5 sig f 3 sig fig g/mL

6. Metric System (SI): (bu = base unit = gram, liter, or meter)
kilo- k x 1000 or
centi- c x 0.01 or
milli- m x or
micro- μ x or
Examples:
1.25 mL  L mL x = L
87.5 kg  g kg x = g
0.05 m  μm m x = μm
*Don’t forget the unit!
*Does it make sense?
1000 bu
1 k
1 bu
100 c
1 bu
1000 m
1 bu μ
1 L
1000 mL
1000 g
1 kg μm
1 m

7. Definitions: Accuracy Atom Precision Chemical bond
Quantitative Homogeneous
Qualitative Heterogeneous IV DV
Controlled variable
Theory
Law
Physical change
Chemical change
Discrete
Continuous
Line graph
Bar graph
Mixture
Solution
Element
Compound

8. How to study chem:
-Learn vocabulary (with examples) so you know the word when its used in a question
-Look for similarities in problems & use the same steps
-Break down problems into steps – identify what you are given & what you need to solve
-Keep up with the work

9. Calculator Tips: -Exponents can look like: 00 EXP EE
-Use parentheses when typing in sci not or fractions
-Use ÷ for dividing fractions
-Use +/- for negative numbers (not the subtract button)