Using Metric Tools

1. Ruler

• The ruler above has an English side that uses inches and a metric side that uses centimeters. We will only use the metric side in this class.

• On the metric side the lines with numbers measure centimeters and the smaller lines measure millimeters.

• There are 10 millimeters in one centimeter.

Reading a Ruler

In science, the last digit of a measurement is always estimated.

Fractions are not used. When measuring with a ruler, 2 decimal places are needed when using cm and 1 decimal places are needed when using mm.

Letter A above indicates a measurement of 0.59 cm or 5.9 mm.

Reading a Ruler

The correct measurement for B is _______ cm or _________ mm.The correct measurement for C is ______cm or ______ mm

Reading a Ruler

The correct measurement for B is 1.20 cm or 12.0 mm.The correct measurement for C is 2.19 cm or 21.9 mm

Reading a Ruler

D is

E is

F is

G is

D

↓G

↓

Reading a Ruler

2. Graduated Cylinders Always Read to the Bottom of the Meniscus.

The meniscus is the curved water line that occurs due to attraction of water to glass.

Graduated cylinder should be at eye level when determining the volume.

                                                                           

Graduated Cylinders

Graduated Cylinders

3. Thermometers

Thermometers

4. Triple Beam Balance

Before using a TBB you must zero the balance.

To do this all riders must be sitting in the slots on the far left of the balance and nothing should be sitting on the weighing platform.

If the indicator shows a reading other than “0”, there is a small knob under the left side of the weighing platform. Turn this knob slowly until the two white lines are lined up.

TBBread

Triple Beam Balance

Turning the calibration knob clockwise will move the pointer down and turning it counterclockwise will move it up.

TBBread

To measure out a specific quantity of a powder or crystalline substance:

Determine the mass of the container that will hold the substance.Add this quantity to the mass you want. For example if you want to measure out 5 grams of salt and its container has a mass of 4 grams, you come up with the number 9 grams.Set the riders for 9 grams.Slowly pour salt into the dish until the indicator levels off at zero.

5. To Measure Volume

Cube: Side³

Rectangular solid: L • W • H

Cylinder: πr²h

Liquid: Use graduated cylinder

Volume of small irregular shaped objects

• Pour more than enough water in a graduated cylinder to cover the object.

• Record the amount of water in the cylinder.

• Drop the object into the graduated cylinder and record the new amount.

• Subtract the first value from the second value.

• Include the units (usually cm³ ) in your measurement.

• 1 ml = 1cm³

To find surface area

• For a rectangular surface: L x W

• For a circular surface: πr²