Review of General Science Information Getting Started Review of General Science Information

Scientific Method A systematic approach to solving a problem; a series of logical steps. Typical steps involved: Observation Hypothesis Experiments Data analysis Conclusions

Significant Digits The number of significant digits in a measurement depends on the precision of the measuring device. When making a measurement, you should always estimate one digit more than the marked divisions. The number of significant digits in a measurement is all of the certain digits plus one estimated digit.

Significant Digits When a measurement is provided, the following rules apply: All nonzero figures are significant. When a zero falls between nonzero digits, the zero is also significant. When a zero falls after the decimal point and after a significant figure, that zero is significant. When a zero is used merely to indicate the position of the decimal, it is not significant. All counting numbers and exact numbers are treated as if they have an infinite number of significant figures.

Examples 3.507 cm 0.004 m 268 K 6.571 kg 28.0 mL 2500 L 0.0230 mm 0.106 g

Calculations with significant figures To add or subtract measurements, first perform the mathematical operation, then round off the result to the least precise value. There should be the same number of digits to the right of the decimal as the measurement with the least number of decimal digits.

Calculations with significant figures To multiply or divide measurements, first perform the calculation, then round the answer to the same number of significant digits as the measurement with the least number of significant digits. The answer should contain no more significant digits than the fewest number of significant digits in any of the measurements in the calculation.

Examples 3.402 + 42.10 = 21.3 – 16.43 = 3.412 x 0.005 = 1745.2 / 200 =

Scientific Notation Used by scientists to express very large or very small numbers. A number written in scientific notation has only one digit to the left of the decimal point.

Positive Exponents A positive exponent tells how many times the number must be multiplied by ten to give the expanded form of the number. You can also think of a positive exponent as the number of places you move the decimal to the right.

Examples 4.12 x 107 = 41,200,000. 7.2 x 103 = 1.364 x 106 =

Negative exponents A negative exponent tells how many times a number must be divided by ten to give the expanded form of the number. You can also think of a negative exponent as the number of times you move the decimal to the left.

Examples 3.404 x 10-5 = 0.00003404 7.13 x 10-3 = 6.003 x 10-10 =

Representing Data Bar Graph Pie Chart Line Graph Linear relationship y = mx + b Inverse relationship y = a / x Quadratic relationship y = ax2 + bx + c