Finite Math: Set Operations and Notation

I found this usefull info on this site, and had to copy it some where I could find it again. http://accesstech.co.za/?p=2074

Useful USSD codes for South African Mobile networks

USSD codes (Unstructured Supplementary Service Data)
Option	Network	USSD Code	Further instructions and _ or notes
Change Price plan and or tariff	MTN	*141*4#	key in “2” (migrate), then key in a that corresponds with the price plan you’d like to migrate to.
Airtime transfer	MTN	*141*6328* recipient’s cell phone number* rand amount#	For example: *141*6328*0731234567*30#).
Airtime transfer	Vodacom	*111#	Option 4 (bundle or airtime transfer) >> option 1 (airtime) >> choose an amount from R29 to R2000 >> enter a Vodacom number >> Confirm and you’re done.
Airtime transfer	Telkom Mobile (8ta)	*180#	Option 2 (transfer airtime) >> choose the amount >> enter an 8ta cell number >> confirm and you’re done.
Request airtime	MTN	*141*6328*number of the person sending you airtime#	Two requests are permitted per day.
Balance Enquiry	MTN	*141#	Your airtime, SMSs and your MTN internet bundle balance will be displayed.
Airtime recharge	MTN	*141* recharge voucher pin #
Data bundle purchase	MTN	*141*6#	Key in “1” (purchase bundles and services) >> key in “1” (internet bundles) >> key in “1 – 3” (the 3 options are for Volume bundles, duration bundles, and uncapped bundles respectively)
Deactivate an uncapped data bundle	MTN	*141*5#	key in “2”.
Loyalty points program	MTN	* 141 * 9 * your ID number#	A program where MTN rewards its customers with points to buy airtime, bundles, enter competitions etc.
Call charges	MTN	*111*2#	key in “1 – 2” (the two options are for number and country respectively)
Callback	MTN	*121* recipient’s number #	You are permitted five callbacks a day on the MTN network.
Check your own number – MSISDN query	MTN	*123*888#	This will display the number from where this USSD code is dialed.
Check your own number – MSISDN query	Vodacom	*111*501#	This will display the number from where this USSD code is dialed.
MMS OTA settings request	MTN	*123*12#	You will receive a configuration message to install the settings, if asked for a pin, enter 1234.
WAP/GPRS/Internet OTA settings request	MTN	*123*12#	You will receive a configuration message to install the settings, if asked for a pin, enter 1234.
Easy recharge	MTN	*141*10#
Point of interest request	MTN	*120*555#	An MTN service to find useful points of interest (POI) located closest to you like an ATM, fast food outlets, movie theatres etc.
Registering/Opening a Mobile Money account	MTN	*120*668#	You have to be at least 16 years to qualify for this service.
Cancelling a Recurring Bundle	MTN	*141*5#	key in “1”.
My Vodacom USSD services menu	Vodacom	*111#	this menu includes popular services
Balance Enquiry	Vodacom	*100#	your balance is displayed on handset (Prepaid Only)
Airtime recharge	Vodacom	*100*01*Recharge PIN#	Account top up with voucher value (Prepaid Only)
Time Window Enquiry	Vodacom	*100*02#	Time Window Expiry date displayed on handset (Prepaid Only)
Vodata Service Setup	Vodacom	*141*777#	Vodata Service Setup menu will be installed or removed (Contract & Prepaid)
Please CallMe Service	Vodacom	*140*MSISDN#	Sending a text message which includes the sender’s number to another cell phone number requesting the receiver to call the sender (Contract & Prepaid)
Please Recharge Me	Vodacom	*140*02*MSISDN#	Request airtime from your phone to any Vodacom customer
Airtime transfer	Vodacom	*102*02*airtime value*MSISDN#	Send airtime from your cellphone to any other Vodacom Prepaid phone
Vodacom Paypoint	Vodacom	*120*1234#	Enables Vodacom merchants to accept credit card payments using a mobile phone without requiring a fixed line point of sale terminal
Cell C USSD services menu	Cell C	*147#	Launches the USSD menu with various account management and inquiry options.
Balance Enquiry	Cell C	*101#	Displays the remaining balance on your handset
Airtime recharge	Cell C	*102*#	Account top up with voucher value
Please CallMe Service	Cell C	*111*#	Sending a text message which includes the sender’s number to another cell phone number requesting the receiver to call the sender (Contract & Prepaid)
Check your own number – MSISDN query	Cell C	*147*100#	(retrieve own number)
Manage subscription services	Cell C	*133*1#
Virgin Mobile menu	Virgin Mobile	*100#	Launches the USSD menu with various account management and inquiry options.
Get phone settings	Virgin Mobile	*103*1#
Check your own number – MSISDN query	Virgin Mobile	*103*2#	(retrieve own number)
Change Virgin Mobile PIN	Virgin Mobile	*103*3#
Balance info after calls	Virgin Mobile	*103*4#
SIM Swap	Virgin Mobile	*103*5#
Manage airtime	Virgin Mobile	*104#
Check balance	Virgin Mobile	*101#
Airtime recharge	Virgin Mobile	*102* PIN #	Account top up with voucher value
Credit card recharge	Virgin Mobile	*104*3#	You need to register for this service by dialing 123 from your Virgin Mobile device
Transfer airtime	Virgin Mobile	*106#	You can only transfer airtime to other Virgin Mobile users.
Please CallMe Service	Virgin Mobile	*125*MSISDN#	Sending a text message which includes the sender’s number to another cell phone number requesting the receiver to call the sender (Contract & Prepaid)
Voice Mail	Virgin Mobile	*109#
RICA check	Virgin Mobile	*124#
Bundles	Virgin Mobile	*110#	Sms, data and Blackberry bundles
Transfer airtime	Virgin Mobile	*106#
Recharge me	Virgin Mobile	*104*5#
Call handling	Virgin Mobile	*107#
Airtime advance activation	Virgin Mobile	*121*4#	(Prepaid only)
Roaming call	Virgin Mobile	*108*MSISDN#

So what is USSD exactly?
Unstructured Supplementary Service Data (USSD) is a technology that allows users to access various services through the use of short codes. It usually consists of a number that start with a * and end with a #.

Customers on prepaid, for example, often use USSD codes to load airtime:

Let’s take MTN as an example:

Load airtime voucher: (*141*VoucherPIN#)
check balances: (*141#)
send a please call me: (*121*CellphoneNumber#).

So, here is a list of USSD codes for all the mobile networks in South Afica.

I will update this list so, yet again, please feel free to provide input regarding errors, ommissions and anything else.