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p. 1: When you begin with operations, make the learners aware that the four operations (addition, multiplication, subtraction and division) involve only two different processes:
Two processes Together Separate
This includes concepts like: Add togetherJoinAltogether Take awaySeparateHand out/Divide
Four signs + x _ ¸
differentgroups equalgroups differentgroups equalgroups
Look at schematic representations
+12 + 14 = 35 -26 - 12 = 14
x5 x 3 = 15 ¸30 ¸ 3 = 10
The more the learners see this representation, and hear the explanation, the better they will understand and be able to apply it when solving problems.
The learners must understand the commutative property of addition
(3 + 4 = 7 and 4 + 3 = 7 ) and multiplication ( 2 x 5 = 10 and 5 x 2 = 10 ), but they need not know or use the words “commutative property”.
p. 2: The learners must understand the associative property of subtraction
(9 – 4 = 5 and 9 - 5 = 4 ) and division ( 10 ¸ 2 = 5 and 10 ¸ 5 = 2 ).
p. 3: Learners must first experience with concrete objects how the answers to the subtraction operations can be checked: return what you have taken away and if you have the number you began with, you know your answer is correct. Later this can then be done in writing.
Encourage them to check regularly and later they will do it automatically.
Number sentence: 3 + 4 = 7
Let’s have Bonny and Tommy change places:
Number sentence: 4 + 3 = 7
LO 1.9 |
Number sentence: 9 - 4 = 5
Number sentence: 9 - 5 = 4
The numbers on either side of the = sign can change places.
Watch 9 - 4 = 5
carefully! 9 - 5 = 4 Now do the same with:
LO 1.9 |
Number sentence: 9 - 4 = 5
Check! Put everything you took away and everything that was left, together again. If you have the same number that you started with, your calculation is correct.
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 1.9: We know this when the learner performs mental calculations involving:
1.9.1 addition and subtraction for numbers to at least 50;
1.9.2 multiplication of whole numbers with solutions to at least 50.
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