Measurement and Units

Rulers- Do NowHow do you read a ruler?Why are rulers important?What are some examples of careers where rulers are necessary?

Reading a Ruler

Some Things To Note:Each long line labeled with a number

represents the whole number place(s)Each smaller line is a fraction, decimal

or “A little bit more” of that whole number

When measuring in centimeters, each smaller line is worth 0.1 (a tenth of a centimeter)

Add to get the full value to the nearest tenth

If on a whole number line, add .0 if the measurement needs to be to the nearest tenth

Example: __________

ROUNDING

Rules for Rounding

1. When rounding to a place, look to the number to the right of the number in question.Example: If you are rounding to the nearest tenth, look at the hundredths place

2. If the number to the right isa. Less than 5, keep the number the same and drop all numbers to the rightb. Equal to or greater than 5, increase the number in question by 1 and drop the numbers to the right

Round to the nearest tenth:

7.8832

Round to the nearest thousandth:

234.24325

UnitsUnits tell you what is being

measuredDistance is measured in: meters,

centimeters, millimeters, miles, feet, etc and is measured with some kind of ruler

Mass or weight is measured in: grams, kilograms, pounds and ounces and is measured with some kind of scale

Units and MathWhen adding or subtracting

numbers with the same units, the units stay the same

A. Example: 2 grams + 8 grams = 10 gramsWhen multiplying units that are

the same, each time you “times” an exponent is added

A. Example: 3 grams *2 grams * 4 grams = 24 grams cubed

When multiplying different units, they carry

A. Example: 2 oranges X 5 apples = 10 apples X orangesWhen dividing, units that are

the same on the top and bottom cancel out

A. Example:

If dividing and the units are different, carry them through

A.