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  • GETIntPhaseMaths display tagshide tags

    This module is included inLens: Siyavula: Mathematics (Gr. 4-6)
    By: Siyavula

    Review Status: In Review

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To perform mental calculations

Module by: Siyavula Uploaders. E-mail the author

MATHEMATICS

Division

EDUCATOR SECTION

Memorandum

LEANER SECTION

Content

Activity: To perform mental calculations [LO 1.9.3]

  • Let us play a game!

Play with a friend. You will each need a dice and sixteen markers. Make two boards of stiff cardboard that look like this:

  • Each player now writes the following numbers on his board. You may write them where you want to.

20 ; 24 ; 32 ; 39 ; 40 ; 41 ; 48 ; 57 ; 59 ; 61 ; 66 ; 68 ; 69 ; 79 ; 86 ; 90

  • When you are ready, number 1 throws the dice.
  • The number that shows on the dice, is the REMAINDER that you will get when you divide a number on the board by 7. Close that number with one of your markers. Take turns to play. The player whose board is full of markers first, is the winner.

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 1.9: We know this when the learner performs mental calculations involving:

1.9.3: division with small numbers.

TEST 20

1. Fill in the missing words:

1.1 Any number divided by 1 is____________________________________

1.2 When we divide a number by 2, we say we ________________________

the number. (2)

2. Complete the following flow diagrams:

Figure 1
Figure 1 (graphics1.png)

Figure 2
Figure 2 (graphics2.png)

(3)

3. Estimate the quotient by first rounding off the divisor to the nearest 10 and the dividend to the nearest 100:

3.1 2 468 ÷ 47 = __________________________________________

= _______________________________________(2)

3.2 3 639 ÷ 33 = __________________________________________

= _______________________________________(2)

4. Valerie had to calculate the following: 32 876 ÷ 26. She started, but could not complete the calculation. Complete the sum for her.

Table 1
        1      
2 6   3 2 8 7 6
    - 2 6      

_______________________________

_______________________________

_______________________________

_______________________________

_______________________________

_______________________________

_______________________________

_______________________________ (3)

5. Calculate the following without a calculator:

5.1 A fruit vendor buys 8 498 apples and packs them in boxes containing 35 apples each. How many boxes does he need?

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________ (4)

5.2 How many rolls of chicken netting is needed to fence a camp of 1 598 m if each roll contains 45 m?

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________

__________________________________________________________ (4)

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Definition of a lens

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A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

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