3. Now, You Need to Calculate the Drawing Magnification

Drawing Calculations: Extra Help!

1.  Begin by measuring the length and width of the specimen using the reticule. Convert to µm using the conversion table provided to you.

2.  Convert the measurements of the length and width into mm by using the process of “dimensional analysis.” This conversion will give you the life size of your specimen in mm.

v  For example, you measure the width of your specimen to be 306 divisions on your reticule under the 400x objective. What is the life size width of the specimen in mm?

3. Now, you need to calculate the drawing magnification.

Since you measured a 100 mm by 100mm box, divide 100 by your largest life size measurement. Round this number to a “workable number”.

Ex. 1428 can be rounded to 1400.

This will equal the drawing magnification and is written as “______x L.S.”

4. To calculate the drawing dimensions, multiply each life size by the drawing magnification. This is the size that your drawing should be made on your paper.

5. To finish the drawing, be sure to include the proper labels and use the provided checklist for scientific drawings.

Making Your Drawing

Drawing Box

1.  Draw a horizontal line 25 mm down from the top of the page

2.  Draw a horizontal line 100 mm down from your previous horizontal line

3.  Draw a vertical line 25 mm from the left edge of the page

4.  Draw a vertical line 90 mm from the right edge of the page

You should have a 100mm x 100 mm box with a 90 mm margin to the right of the box

Labeling

1.  Labels begin at the end of label line- not written on top of the label line

2.  Labels are printed neatly and spelled correctly

3.  Name of object printed below on the left side of the drawing

4.  Microscope magnification printed clearly in right margin

5.  Life size is printed clearly below microscope magnification in right margin

6.  Drawing magnification is printed clearly below life size in right margin

Here is the scoring guide that will be used for grading your scientific drawings.

___ Box is placed in correct part of paper (25mm over, 25 mm down)

___ Only 2 drawing per piece of paper

___ Enlarged drawing

___ Use ruler for lines and keep lines parallel

___ Lines stop at 70 mm from the margin and all lines stop at the same point creating an

imaginary margin.

___ Do not label on the lines- label at the of the line

___ Labels are printed

___ Spelling of labels is correct

___ Specimen is colored

___ Use typing paper

___ Name of object is printed beneath drawing

___ Microscope magnification is correctly indicated (“microscopic magnification ___x)

___ Life size of the object is correctly indicated (units, 2 dimensions)

___ Drawing magnification is correctly indicated (___x LS, no units)