Counting

Mathematics

Grade 4

Whole numbers and their relationships

Module 1

Counting

ACTIVITIES:

• Count forwards and backwards in 2s; 3s; 5s; 10s; 25s; 50s and 100s

from 0 to 10 000 [LO 1.1]

• Begin to use a calculator [LO 1.10]
• Begin to perform mental calculations involving addition and subtraction [LO 1.9]
• Begin to solve problems in context [LO 1.6]

NUMBERS, OPERATIONS AND RELATIONSHIPS

• Numbers are wonderful. We need them every day in our lives. Welcome to the wonderful world of numbers, figures and symbols. We hope to travel with you on the journey of exploration in the world of numbers, so let’s start.

1. COUNTING IN THE EVERYDAY WORLD

• In the Foundation Phase you learnt to count to at least 1 000. See how well you can complete the following exercise:
• Each day airlines need to work with many numbers. Imagine you are a member of a ground crew and you are counting paper coffee mugs for the passengers on an aircraft.

1.1 You are counting them in 2s and have reached 592. Write down the next five numbers:

1.2 Now you decide it is quicker to count them in 5s. You reach 980. Write down the next five numbers:

1.3 You are still counting paper cups for the aircraft but now you decide to count them in tens. You have reached 660. Write down the next five numbers:

1.4 Now you are in a hurry! You count them in 25s. You reach 725. Write down the next five numbers:

1.5 You have enough paper cups for a month! Count them in 50s from 800 to one thousand and fifty and write down these numbers:

1.6 The plane is about to take off! Now you are really in a hurry! Count them in hundreds from 0 to 1 100 and write down the last five numbers:

1.7 The distance from Cape Town to Johannesburg is one thousand, four hundred and two kilometres. Write this distance in numbers:

2. MAKING YOUR CALCULATOR COUNT

• Now we know you can count to 1 000. Can you make your calculator count in 2s without pressing  2 each time?

HOW TO MAKE YOUR CALCULATOR COUNT:

2.1 Clear your calculator.

Press 2  = = = =

Some calculators need the command: 2   = = = = or

2  K = = = =

Get to know your calculator.

2.2 Make your calculator start at 1 004 and count on in 2s

Clear your calculator. Now press 1 004 + 2 = = = =

Some calculators need: 2 + + 1 004 = = = =

2.3 How will you make your calculator “count backwards”?

Clear your calculator. Begin with 7 190 and count backwards in 2s.

Some calculators need: 2 - - 7 910

Always remember to clear your calculator before you begin. Now you are ready to begin the “Group Work”.

You should do the next few exercises for five minutes each day for the rest of the first term at least, until you find them really easy. Numbers may be changed.

3. COUNTING FORWARDS AND BACKWARDS (Oral group work):

Now that you have learnt how to make your calculator count backwards and forwards in intervals, check that you can still do so too, aloud. You may work in groups. Only one learner in each group will be using a calculator. Your educator will explain how to play this game, so listen carefully.

3.1 Count on in 2’s from 186 to 204. Count backwards in 2s from 208 to 194.