Everything Life Sciences Grade 10

1.8 Mathematical skills in Life Sciences DUMMY

Mathematical skills are important in Life Sciences. Below are explanations of some of the

skills you will encounter.

NB.You must state the UNITS at the end of each calculation, e.g. cm, degrees, kg, etc.

Scales

A scale is given in a diagram, drawing or electron micrograph so that the actual size of the

object that is being shown can be determined. The object could be bigger or smaller in real

life.

Example: To measure the diameter of a chloroplast with a scale line of 1μm.

1) Measure the length of the scale line on the micrograph in mm, e.g. 1μm = 17mm

2) Measure the diameter of the organelle in millimetres, e.g. = 60mm

3) True diameter of chloroplast:

=

measured size × true length of scale line

measured length of scale line

=

60 mm× 1 μm

17 mm

=3,53μm

Averages

To find an average of a set of numbers, you add all the items and divide the total by the

number of items.

Example: Find the average height in a class of 10 learners with the following heights in cm:

173, 135, 142, 167, 189, 140, 139, 164, 172, 181 cm.

Total = 1602 (add all 10 heights together)

Average

Average =

1602

10

=160,2 cm

Percentages

To calculate a percentage, multiply the fraction by 100.

Formula for calculating percentage (%):

Percentage =

Number with feature(A)

Total number(B)

times 100

Example: Calculate the percentage of learners in your class that are left-handed.

20 1.8. Mathematical skills in Life Sciences