4.3 Multiplication and division

Mathematics

Bonny and tommy’s school féte

Educator section

Memorandum

It is imperative that the educator is familiar with the content of this module before it is given to the learners, as this module contains advanced and enrichment work. Learners in the first two groups should find it a challenge and should be able to cope with it. Do not expose learners to tasks that are too difficult for them and which frustrate them. (Select according to their abilities).

The activities, the construction of mobiles, can be done classically. They can be combined with Technology.

Number Concept to 1 500

Operations:

• Addition, subtraction and multiplication – two and three digit numbers with and without regrouping of the tens and the hundreds;
• Division – two digit numbers with regrouping of the tens and remainders,
• e.g. 66 ÷ 4 =

In Module 7 number concept is extended to 1500. All addition, subtraction and multiplication calculations are performed with 2-digit and 3-digit numbers with and without regrouping of hundreds and tens. Division is only done with 2-digit numbers with regrouping of tens, with a remainder e.g. 66 ÷ 4 =

A discussion about the féte is necessary beforehand so that the learners may order their thoughts and plan the picture.

The learners must understand counting onwards from one thousand very well. Use similar number blocks from 1 101 to 1200, 1201 to 1300, 1301 to 1400 and 1401 to 1500 if necessary.

Shopping games should be used to help learners to calculate change.

Give special attention to equal quantities of and mℓ.

Use the posters for more calculations and provide opportunities for the learners to ask one another to do certain calculations.

This is an activity to be done on the playground. Let the learners measure with a trundle wheel.

Learners are expected to be able to count in a language other than their home language. If there are learners in the class who are proficient in another language, they should be given the opportunity to do so.

These involve consolidation of operations. Attend to problem areas.

The calculations of fractions of numbers may cause problems for some learners. Encourage them to try, even if they only accomplish the easier ones.

The 8x and ÷ are done simultaneously with eights. It is not compulsory for them to know these.

Multiplication is done with regrouping of hundreds as well as tens.

This activity tests the learners’ knowledge of numbers and reasoning abilities.

Division with regrouping the tens and a remainder requires much practice in the concrete. Learners must be able to say how they think and what they are doing before they attempt written work. Much practice is needed.

Encourage learners to test their operations.

This activity cannot be completed in one day. It can be combined with Technology. If there is not enough time, learners can be divided into groups of 5 to allow each learner to complete 1 shape, in which case the group will make a collective mobile sharing all knowledge with one another. If they find folding and pasting the round edges of the cone and cylinder they can paste these on the outside or they can cut off the round edges.

The shapes should preferably be duplicated on manilla, but if this is not available, use ordinary paper.

Leaner section

Content

Activity: multiplication and division [lo 1.1, lo 1.8, lo 1.8, lo 1.10]

• The 3 ladies baking the pancakes have already each finished 142.
• How many did they bake altogether?

Use the method that you prefer to solve these problems.

• Dad, Mom, Bonny and Tommy each collected R94 for the school. What is the total amount that they collected altogether?
• Tommy and Robby each picked up 157 empty cool drink tins to throw into the bin. How many tins did they pick up altogether?

• Write your own story to match the number sentence. Do the operations.

86 x 3 = ________________________________

136 x 5 = _______________________________

• Complete:

Operations:

Addition: We find the sum or the total.

Subtraction: We find the difference.

Multiplication: We find the product.

Division: We find the quotient.

• Complete the sentences with the correct answers:

1. The total of 19, 10 and 25 is ______________________________________

2. The difference between 45 and 54 is _________________________________

3. The product of 23 and 4 is _________________________________________

4. The quotient of 36 and 2 is ________________________________________

5. The half of 96 is _______________________________________________

6. Thirty five is the half of ______________________________________

7. One hundred and twenty five doubled is ______________________________

8. Eight quarters are _______________________________________________ wholes.

9. The sum of two numbers is 145. The one number is 115 and the other number is ________________________________________________________

• Dad has 54 marbles and he wants to divide them equally among 4 boys. How many marbles will each get and how many will be left over?

Ø I always test my answers by doing the opposite operation.

Ø I test a division operation with a multiplication.

Assessment

Learning Outcome 1: The learner will be able to recognise, describe and represent numbers and their relationships, and to count, estimate, calculate and check with competence and confidence in solving problems.

Assessment Standard 1.1: We know this when the learner counts forwards and backwards;

Assessment Standard 1.4: We know this when the learner orders, describes and compares numbers;

Assessment Standard 1.8: We know this when the learner can perform calculations, using appropriate symbols, to solve problems;

Assessment Standard 1.10: We know this when the learner uses the following techniques:

1.10.1 building up and breaking down numbers;

1.10.2 doubling and halving;

1.10.3 number-lines;

1.10.4 rounding off in tens.