# Estimating and measuring

```SCIENTIFIC
PROCESSES
Estimating and Measuring
YOU SHOULD BE ABLE TO:
• following a sequence of diagrammatic and written
instructions and record estimates and measurements
• use appropriate techniques; handle apparatus/material
competently and have due regard to safety
• calculate magnification
• state the functions of the various parts of the
microscope
• estimate or measure, volume, length, mass, time/rate
and temperature
• records and organise data using standard
measurements
• convert units of volume, length, mass, and temperature
APPARATUS THAT
MAGNIFIES OBJECTS
• To magnify means to make something look bigger
• Apparatus that can magnify an object can be
divided into two categories:
1. Hand lens
2. Microscope
HAND LENS
• A hand lens has a convex glass or plastic lens to
bend light, making objects look bigger.
• The frame shows by how much an object can be
made bigger when looking through the lens.
• A stronger magnification shows more detail in a
small area.
• A weaker magnification shows less detail in a
larger area.
CALCULATING
MAGNIFICATION
1. Measure the length of specimen in the drawing and
in real life. (indicate from where until where you are
measuring)
2. Use the formula:
• E.g.
Actual
𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝑠𝑖𝑧𝑒
𝑚𝑎𝑔𝑛𝑖𝑓𝑖𝑐𝑎𝑡𝑖𝑜𝑛 =
𝑎𝑐𝑡𝑢𝑎𝑙 𝑠𝑖𝑧𝑒
• Magnification does not have a unit. It only has a
𝑚𝑎𝑔 =
𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑
𝑎𝑐𝑡𝑢𝑎𝑙
3,8𝑐𝑚
𝑚𝑎𝑔 =
=&times; 1,9
2𝑐𝑚
CALCULATING THE SIZE OF
AN OBJECT USING
MICROGRAPH SCALE LINE
• A micrograph is a photo of a structure or object
seen under the microscope field.
• A scale line or bar is shown on a micrograph to
calculate the actual size of the object.
• To do so you have to follow the following steps.
CALCULATING THE SIZE OF AN
OBJECT USING MICROGRAPH
SCALE LINE (CONTINUED)
1. Use a ruler to measure
the length of the scale
line
2. Measure the length of the
specimen
3. Use the formula to work
out the actual size
4. Round off to the nearest
decimal
E.g.
the scale line = 35mm =100&micro;m
The specimen = 70mm
70𝑚𝑚
Then
&times; 100𝜇𝑚 = 200𝜇𝑚
35𝑚𝑚
```