1. Calculate the linear magnification of an image
Three metric units that will be useful for this and all future microscope activities are the millimeter (mm) and micrometer (μm) and nanometer (nm)
(*The micro symbol ‘μ’ looks like a ‘u’ with a longer tail in the front)
1 meter (m) = 1000 millimeters (mm)
1 millimeter (mm) = 1000 micrometers (μm)
1 micrometer (μm) =1000 nanometers(nm)
m= or 1m
mm= or 0.001m
μm = or m
Let’s read the Magnification in Biology Sheet

2. Before we begin:
Note:
Numbers written like this: 1.26 x 105 mean you move the decimal point to the right. In this case you move it 5 times:
1.26 x 105 = .

3. magnification is 40,000 then:
The actual size of an object can be calculated using the same formula:
Magnification =
Image size
Actual
size of object
MIA
Therefore:
Actual
Size of object =
Image size
Magnification
AIM
If an image is measured and found to have a length of 6 mm (6,000 mm) and the
magnification is 40,000 then:
Actual size of object =
6,000
40,000
= 0.15 mm

4. Let’s look at the worked examples:
Worked example 1: Calculation of the magnification of a drawing
Worked example 2: Calculation of magnification and conversion of units
Worked example 3: Calculating magnification from a scale bar
When we are happy with this you will move onto some individual tasks

5. Task: 10 minutes
Read the calculating linear magnification sheet and go through worked example again
THEN Complete the calculating linear magnification sheet 8 marks
Cell Magnification practice 10 marks
2 x 2 mark exam questions
1x 8 mark exam question
ARE WE HAPPY NOW???

6. Plenary:
Complete the examination question
10 marks =10 minutes