Lesson 4 - Simple Math and Algebra Concepts for Opticians

Question 1

Transformation

Answer 1

Performing the same action on both sides of an equation in order to isolate an unknown variable

Example 1:

A - 5 = 32
Simply add 5 to both sides
A - 5 +5 = 32 + 5
A = 37

Example 2:
A x 2=16
Simply divide each side by 2
(A x 2) / 2 = 16 / 2
A = 16 / 2
A = 8

Example 3:

(A + 2) / 3 = 20
step 1: multiply 3 to both sides
3 x ((A + 2) / 3) = 20 x 3
A + 2 = 60
step 2: subtract 2 from both sides
A + 2 - 2 = 60 - 2
A = 58

Example 4:

(A / (5/9)) = 13
multiply the inverse of the fraction (5/9) to both sides
(9/5) x (A / (5/9)) = 13 x (9/5)
A = (117/5) 
A = 23.4

Question 2

Manual lensometer

Answer 2

An instrument used to read the power of prescription lenses

Question 3

How many inches are in 1 meter?

Answer 3

1 meter (m) = 39.37 inches (in)

Question 4

How many inches are in 1 centimeter?

Answer 4

1 centimeter (cm) = .394 inches (in)

Question 5

Reciprocal

Answer 5

When dividing fractions, flip the second fraction so that you can multiply instead of divide.

Example

((1/2) / (3/4)) = ?
Flip second fraction and multiply instead of dividing
((1/2) x (4/3)) = 4/6
Simplify answer
= 2/3

Question 6

Convert 1mm to inches

Answer 6

1mm = .039in