MATHEMATICS AND SCIENCE

Estimate

An estimate is an approximation of a number based on reasonable assumptions.

Not the same as guessing!!!Based on known info

Scientist must sometimes rely on estimates when they cannot obtain exact numbers

Accuracy and Precision

Accuracy – refers to how close a measurement is to the true value.

Precision – refers to how close a group of measurements are to each other.

Neither Accurate or Precise

Accurate and

Precise

Precise but not

Accurate

Significant Figures

The significant figures in a measurement include all the digits that have been measured exactly, plus one whose value has been estimated.

Several ways to determine the average number.1. Mean - is the numerical average by adding up

all the numbers and then dividing by the total number of items in the list.

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Mean

Test scores: Mean =

88947290

Several ways to determine the average number.2. Median – the middle number in a set of

data.- Place all the numbers in order from

smallest to largest. Circle the middle number.

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Median

110 102 110 107 94 110 109

Median =

Several ways to determine the average number.

2. Mode – the number that appears most often in a list of numbers.

- Place all the numbers in order from smallest to largest.

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Mode

110 102 110 107 94 110 109

Mode =

Percent Error

Percent error is used to determine how accurate, or close to the true value an experimental value really is.

Graphing A graph is a useful tool that may help

scientist interpret data by revealing unexpected patterns.

Line graph – shows how the responding or dependent variable changes in response to the manipulated or independent variable. The horizontal axis – runs left to right. The vertical axis – runs up and down. Includes a line of best fit – this shows the

overall trend of data. If a graph shows no identifiable trend then there

is no relationship between the variables

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A line of best fit emphasizes the overall trend shown by all the data taken as a whole.

Trend LinesLinear Trends – A line graph in which the points fall on a straight line

Nonlinear Trends – Points don’t fall on the line

No Trend – Points are scattered

A

B

C

Safety in the Science Lab

• Good preparation helps you stay safe when doing science activities in the lab.

• Just as in the lab, good preparation helps you stay safe when doing science activities in the field

• When an accident occurs, no matter how minor, notify your teacher immediately. Then, listen to your teacher’s directions and carry them out quickly.