Tariffs in grade10 mathematical literacy


Financial documents and tariff systems often occur in the context of personal and household finance. For example, you may pay a monthly amount of money for your cellphone account, or your parents may pay a monthly amount for the electricity used by your household. You should receive a till slip with every store purchase you make and if you have a store account, you may well receive monthly accounts that you need to pay off. Understanding how these documents and systems work, and how to manage them is an important part of being able to manage your personal finances.

In this chapter we will learn about:

  • financial documents relating to personal and household finance, including electricity and water bills, phone bills, till slips and account statements.
  • what different items and amounts on these bills and statements represent, and how different values have been determined.
  • tariff systems, including municipal tariffs for electricity, water and sewage, telephone tariffs and transport tariffs for busses, taxis and trains.
  • how to calculate costs using given tariffs and to draw graphs of tariff systems

Domestic electricity in the City of Cape Town is charged for using the tariffs below, for households who use more than 450450 kWh of electricity per month. They refer to each category of electricity usage as a block, and the tariffs are charged in cents per kilowatt hour (kWh). VAT is included in the tariff costs listed below.

Block number (kWh)

cents per kWh (incl VAT)

Block 1 (00 - 150150 kWh)


Block 2 (150,1150,1 - 350350 kWh)


Block 3 (350,1350,1 - 600600 kWh)


Block 4 (>> 600600 kWh)



If Jason's household uses 140140 kWh of electricity in a month, calculate what his electricity bill will be, in Rands.

Thomas uses 200,5200,5 kWh of electricity in a month. What will his electricity costs be in Rands?


In the process of the learning I will be explaining more to the learners about the questions that are difficult to them. I will try by all means to do all the possible examples so that everyone can understand.


According to my experience of teaching 90% of learners will understand this lesson because it is based on the things that are common in their home so am expecting every student to participate  and pass


In the end of the lesson learners will be able to calculate the tariffs and know their formula 


more than 85% will pass this lesson 

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Sisanda Tshefu 216256968