MATHEMATICS

Bonny and Tommy visit the zoo

EDUCATOR SECTION

Memorandum

(In the following module remainders with regrouping of the tens are practised again).

In Module 6 the number concept is extended to 1000. Addition and subtraction is done with two- and three-digit numbers, with and without regrouping of tens and hundreds. Multiplication is done with two- and three-digit numbers with and without regrouping of tens. Division is done with two-digit numbers and regrouping of tens only, without a remainder in Module 6,

e.g. 75 ÷ 5 = ≤ (In the following module, the remainder will be included in regrouping.)

Learners need to know what the actual paper money looks like: R10-, R20-, R50-, R100- and R200-notes.

They must understand the values and be able to do simple calculations.

Explain what drawing to scale signifies. They will have to be able to grasp this concept very well before they will be able to calculate the lengths of the elephants’ trunks. Provide similar examples to ensure that they are able to do the exercise.

The learners need to develop a concrete image of the numerical value of 1000.

999 + 1 completes a ten that is taken to the tens to complete 10 tenswhich make a hundred. The hundred is taken to the hundreds to complete 10 hundreds. These make a group of a thousand which has to be taken to the thousands.

1000: the 1 represents 1 group of a thousand and the 3 noughts are the placeholders for the hundreds, tens and units.

Once the learners have completed the number block, it must be used for many counting exercises in tens and hundreds, counting forwards and backwards.

If learners are still struggling to master doubling and halving, they should be encouraged to use the "cloud" to assist the thinking process.

First work orally with similar examples using letter values, before allowing the learners to do the worksheet.

Multiplication with three-digit numbers, with regrouping of the tens, must first be practised orally and in the concrete.

Let the learners count in 9’s before asking them to write it.

Help them to realise that it is easier to start by adding 10 and subtracting 1 than it is to add 9. The opposite is done when 9 is subtracted: take away 10 and add 1. Let them use counters.

If 10c and 1c pieces are used to explain the idea of regrouping tens during division, the learners will be helped to grasp that the tens have to be broken up and regrouped with the ones before it can be shared out. (Play money could be used.)

The learners may need much practice before they will have enough skill to complete the worksheet.

It might help them to draw the diagrams.

The decision to make use of carried numbers is left to the educator.

First supply paper shapes for dividing into tens, so that the learners may discover for themselves that tenths, like thirds and fifths, have to be calculated and measured. It is not simply a matter of folding and folding again as in the case of a ½ and a ¼ .

Guide them to discover that they, by first obtaining fifths, can divide each fifth down the middle to obtain tenths.

Discuss symmetrical shapes with the learners. Let them identify symmetrical objects in the classroom. They should complete the drawing after this exercise.

LEANER SECTION

Content

ACTIVITY: Scale drawings [L0 1.8, L0 4.5, L0 5.5 ]

Bonny and Tommy enjoyed watching the elephants most of all. There were large ones and small ones.

Figure 1

• Which trunk is the longest? ________________________________________
• Which trunk is the shortest? ________________________________________
• What can you deduce from this? ____________________________________

Each of the spaces between * and * on the number line represents 20 cm. Use any method to calculate the length of each trunk:

Some animals eat meat. They are carnivores.

Others eat plants and they are herbivores.

The carnivores together eat 100 kg of meat every day.

• Complete:

Table 1

Days:	1	2	3	4
Kg:	100

• Their meat is packed in 50 kg packets. How many packets of meat could the keeper make from 400 kg of meat?

He could _____________________________________________________________

This is enough meat for _____________________________________________ days.

• There are 4 cages with birds. They eat 1 kg of seed every day.

How many 250g containers will this make? (Draw the 250g containers.)

• The people at the zoo bought 5 packets of seed weighing 20 kg each. This is enough seed for _________________ days.
• Draw all the 20 kg packets of seed that are needed for 1 year.

• This is how much drinking water is placed in the monkeys’ cages every day:

Figure 2

• Draw the 1ℓcontainers that can be filled from this.
• Draw the 500 mℓ containers that can be filled from this.
• Use your own method to do the calculations.

The small antelope drinks 125 mℓ of milk at a time. He gets milk 4 times per day. How much milk does he drink altogether?

It drinks _____________________________________________________________

• There are 69ℓ of water that have to be taken to 3 lion cages. How many litres of water can be taken to each cage?

Each cage ____________________________________________________________

• One of the monkeys is ill and the vet has said that it must be given 20 mℓ of medicine in the morning and in the evening. How many teaspoonfuls will it drink in a day? Remember: 1 t = 5 mℓ

It will drink ___________________________________________________________

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

Learning Outcome 4:The learner will be able to use appropriate measuring units, instruments and formulae in a variety of contexts.

Assessment Standard 4.5: We know this when the learner estimates, measures, compares and orders three-dimensional objects using non-standard and standard measures;

Learning Outcome 5:The learner will be able to collect, summarise, display and critically analyse data in order to draw conclusions and make predictions, and to interpret and determine chance variation.

Assessment Standard 5.5: We know this when the learner reads and interprets data presented in simple tables and lists.