MATHEMATICS

Bonny and Tommy visit the farm

EDUCATOR SECTION

Memorandum

The learners each need a clock to handle and can construct one out of cardboard before the lesson.

In module 4 the number concept is extended to 600. Addition and subtraction calculations include two and three digit numbers. Multiplication and division calculations are done without regrouping of tens, and only up to 99.

In learning 3x and ÷ up to the 10th multiple, the tables that have to be mastered in Grade 3 are completed. Regular repetition and testing are vitally important from this stage on.

It is recommended that the reading of time be done with all the learners at the same time. Each learner must have a cardboard clock to use when the work is being done.

Such a clock can be made from a paper plate, or the learners can be allowed to design their own clock for Technology. However, it must be ready before the reading of time is started in class. A great deal of practical exercise is necessary before the learners can complete the worksheets.

Number concept is now extended from 400 to 600 and the number blocks of hundreds, tens and units, as well as the flared cards, (attached to Module 2), must still be used to promote the number concept. Give special attention once again to the 100 that must be regrouped when 300 and 500 are halved: 300 = 200 + 100 500 = 400 + 100

Counting in sixes must be done incidentally and can also be repeated on the multiples chart (Module 2). Learners must know: 1 dozen = 12.

Learners must have the opportunity, and be encouraged, to say what they can deduce from the graph, what can change and what will not change, before they have to write about it. Such a discussion will give you a good indication of what the learners understand and which aspects need more attention.

Learning 3x and ÷ must be done on the mat and with the use of concrete apparatus. The worksheets are only there to apply what has already been taught.

Learners must get the opportunity in class, on a daily basis if possible, to take measurements with the ruler, the metre stick and the trundle wheel. The more practice they get, the more accurately they will measure. However, always encourage them to estimate first.

This is enrichment work and if you find that it is too advanced, it can be done at a later stage. There may be learners who would like to accept the challenge.

Seeing that 3x and ÷ have just been done, it is easy to introduce thirds now. Give the learners loose paper shapes and allow them to fold and measure on their own, so that they can discover how it can be done. Some of the learners will know how to find sixths without any help. (Only enrichment)

The idea with the recipe is to make the learners understand that certain standard units and containers must be used, otherwise there is no chance of success with a recipe.

Let the learners mention more examples of the use of standard units in practice, e.g. petrol, milk, mixing medicines, prescriptions for administering medication, etc.

It is essential that all the different standard measuring containers and scales, as well as sand, water and objects used in measuring volume and mass, should be available in the classroom. Learners should be able to experiment every day with measuring and weighing, using standard units: litres and millilitres and grams and milligrams.

A bathroom scale is required to determine the mass of the learners.

Different methods are used for the multiplication and division calculations, but should you prefer another method and you find that the learners understand it better, it is their right to use the preferred method.

It is essential that many similar examples of the relevant number sentences be done orally before the learners are expected to complete this worksheet.

The regrouping of a hundred when adding or subtracting is now formally taught. Sufficient concrete work must be done beforehand. More advanced work where a ten and a hundred are regrouped simultaneously, should not be done at the same time. It will depend on the abilities of the group whether it should be done immediately hereafter or at a much later stage.

Whether the learners will be allowed to make use of carried numbers, remains the decision of the educator. e.g.

Learners will need a blank sheet of paper in order to calculate the shortest route. Some learners may find it difficult and may want to give up, but with a little help they should be able to do it.

A discussion on what they will see as they approach the farmstead by road is necessary before the learners will be able to draw it.

LEANER SECTION

Content

ACTIVITY: Number sentence [LO 1.8, LO 1.10, LO 2.2, LO 3.5]

1. These patterns can help you to work with larger numbers. Complete.

Figure 1

1. 2. See how Bonny and Tommy solved this problem for Grandpa:

Grandpa has 48 pigs on the farm and there are 4 pigsties. How many pigs must he put in each sty?

Number sentence: 48 ÷ 4 = ____________________________

Figure 2

• In the same way, help Granny to solve the following problem: Granny has picked 69 roses and she wants to put the same number of roses in 3 different vases. How many must she put in each vase?

Number sentence:_____________________________________________________

Granny must __________________________________________________________

• Do the calculations and use the method you like best:

42 ÷ 2 = ______________________________________________

68 ÷ 2 = ______________________________________________

96 ÷ 3 = ______________________________________________

63 ÷ 3 = ______________________________________________

84 ÷ 4 = ______________________________________________

44 ÷ 4 = ______________________________________________

• Write a story for each number sentence. Then do the calculation.

35 + 42 + 1 7 = _______________________________________

90 - 53 + 12 = _______________________________________

41 x 2 = _____________________________________________

66 ÷ 3 = _____________________________________________

• Bonny and Tommy have discovered that they sometimes have enough tens to make a group of a hundred.

Number sentence: 56 + 62 = ________________________________________

Figure 3

• Use the method you like best to do these calculations:

73 + 55 = _______________________________________________

46 + 63 = _______________________________________________

94 + 23 = _______________________________________________

• Bonny and Tommyhave also discovered that they sometimes don’t have enough tens to take away and that they then have to regroup a hundred.

Number sentence: 126 - 32 = ________________________________________

Figure 4

• Use the method you like best to do these calculations:

1 18 - 25 = ________________________________________________

150 - 60 = ________________________________________________

147 - 60 = _________________________________________________

• Fill in the answers:

Figure 5

• Complete the number path:

Figure 6

• Fill in the missing numbers:

Figure 7

• Here is a road map for Dad. There are different roads he can take to get to the farm, but which one is the shortest?
• Calculate the shortest road and draw it on the map.

Figure 8

• How long is the shortest road (in km)? _______________________________

• If Dad drives 100 km in one hour, how long will it take him to get there?

It will _______________________________________________________________

• Draw a farm and a house for Grandpa and Granny, as you will see it when you approach the farm.

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;

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.

Learning Outcome 2:The learner will be able to recognise, describe and represent patterns and relationships, as well as to solve problems using algebraic language and skills.

Assessment Standard 2.2: We know this when the learner copies and extends simple number sequences to at least 1 000;

Learning Outcome 3:The learner will be able to describe and represent characteristics and relationships between two-dimensional shapes and three-dimensional objects in a variety of orientations and positions.

Assessment Standard 3.5: We know this when the learner recognises and describes three-dimensional objects from different positions.