## What is Common Factor of two numbers?

Common Factor is a number, that divides into the two numbers, leaving a remainder of zero for both numbers.

Both numbers implies “Common “

Remainder of zero implies “Factor”

## How to find all the Common Factors of two numbers?

For example, there are two numbers 48 and 72, we would like to find out all the common factors of these two numbers

48 = 2 * 2 * 2 * 2 * 3

72 = 2 * 2 * 2 * 3 * 3

The common part of 48 and 72 is 2* 2 * 2 * 3

so the common factor could be

if we pick 1 number: 2, 3

if we pick 2 numbers: 2*2 = 4, 2*3 = 6

if we pick 3 numbers: 2*2*2 = 8, 2*2*3 = 12

if we pick pick 4 numbers: 2*2*2*3 = 24

So all the common factors are: 2, 3, 4, 6, 8, 12 and 24, and the Greatest Common Factor is 24.

## Why need to find Greatest Common Factor?

Greatest Common Factor can be used to simplify a ratio. For example

48 / 72 = （2 * 24）/（3* 24） = 2 / 3

where 24 is the Greatest Common Factor.

## How to reduce the cost of wisdom tooth extraction in Singapore

It could be very expensive for wisdom tooth extraction in Singapore if the
wisdom tooth is impacted, the cost be > 600 per tooth in the private clinic. You may try the following steps to reduce the bill more than 50% if you are SG or PR.

Step 1: Visit Polyclinic and get a refer letter.

Step 2: Visit public hospital to do surgery with the refer letter.

That’s it.

I did a wisdom tooth extraction surgery before at NUH, the cost was 200+ for 1 impacted wisdom tooth with refer letter.

Recently, I visited again for my another wisdom tooth. For my first visit, consultation 81， x-ray 42, subsidy 81, paid 50. Feel grateful.

//An impacted wisdom tooth may partially emerge so that some of the crown is visible (partially impacted), or it may never break through the gums (fully impacted).