# Connexions

You are here: Home » Content » Mathematics Grade 6 » To perform mental calculations

### Lenses

What is a lens?

#### Definition of a lens

##### Lenses

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.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

#### In these lenses

• GETIntPhaseMaths

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

Collection Review Status: In Review

Click the "GETIntPhaseMaths" link to see all content selected in this lens.

Click the tag icon to display tags associated with this content.

### Recently Viewed

This feature requires Javascript to be enabled.

### Tags

(What is a tag?)

These tags come from the endorsement, affiliation, and other lenses that include this content.

Inside Collection (Course):

Course by: Siyavula Uploaders. E-mail the author

# To perform mental calculations

Module by: Siyavula Uploaders. E-mail the author

## Memorandum

INTRODUCTION

The learning programme for grade six consists of five modules:

1. Number concept, Addition and Subtraction

2. Multiplication and Division

3. Fractions and Decimal fractions

4. Measurement and Time

5. Geometry; Data handling and Probability

• It is important that educators complete the modules in the above sequence, as the learners will require the knowledge and skills acquired through a previous module to be able to do the work in any subsequent module.

COMMON AND DECIMAL FRACTIONS (LO 1; 2 AND 5)

LEARNING UNIT 1 FOCUSES ON COMMON FRACTIONS

• This module continues the work dealt with in grade 5. Addition and subtraction of fractions are extended and calculation of a fraction of a particular amount is revised.
• Check whether the learners know the correct terminology and are able to use the correct strategies for doing the above correctly.
• Critical outcome 5 (Communicating effectively by using visual, symbolic and /or language skills in a variety of ways) is addressed.
• It should be possible to work through the module in 3 weeks.
• ** Activity 17 is designed as a portfolio task. It is a very simple task, but learners should do it neatly and accurately. They must be informed in advance of how the educator will be assessing the work.
• LEARNING UNIT 2 FOCUSES ON DECIMAL FRACTIONS
• This module extends the work that was done in grade 5. Learners should be able to do rounding of decimal fractions to the nearest tenth, hundredth and thousandth. Emphasise the use of the correct method (vertical) for addition and subtraction. Also spend sufficient time on the multiplication and division of decimal fractions.
• As learners usually have difficulty with the latter, you could allow 3 to 4 weeks for this section of the work.
• ** Activity 19 is a task for the portfolio. The assignment is fairly simple, but learners should complete it neatly and accurately. They must be informed in advance of how the educator will be assessing the work.

1.1 48

1.2 5

1.3 6

1.4 6

1.5 6969 size 12{ { { size 8{6} } over { size 8{9} } } } {}

1.6 20282028 size 12{ { { size 8{"20"} } over { size 8{"28"} } } } {}

1.7 24362436 size 12{ { { size 8{"24"} } over { size 8{"36"} } } } {}

1.8 16201620 size 12{ { { size 8{"16"} } over { size 8{"20"} } } } {}

1.9 33

1.10 951

1.11 9995

1.12 49

1.13 33

1.14 108

1.15 12

## Content

### ACTIVITY: To perform mental calculations [LO 1.9.1, LO 1.9.2]

Let's see how you cope in the first mental arithmetic test!

 1.1 8 × 6 = ................... 1.9. 37 + .............................… = 70 1.2. 7 × ..............… = 35 1.10. 1 000 – 49 = ......................... 1.3. 42 ÷ 7 = .............…. 1.11. 10 003 – 8 = ........................ 1.4. 54 ÷ ..............… = 9 1.12. 16 + 18 + 15 = ................... 1.5. 2323 size 12{ { {2} over {3} } } {} = 99 size 12{ { {} over {9} } } {} 1.13. 27 + .........................… = 60 1.6. 5757 size 12{ { {5} over {7} } } {} = 2020 size 12{ { {"20"} over {} } } {} 1.14. 12 × 9 = ................….......... 1.7. 66 size 12{ { {} over {6} } } {} = 24362436 size 12{ { {"24"} over {"36"} } } {} 1.15. 96 ÷ ..........................… = 8 1.8. 44 size 12{ { {4} over {} } } {} = 16201620 size 12{ { {"16"} over {"20"} } } {}
 Colour in: My results are GOOD AVERAGE WEAK

#### DO YOU REMEMBER THIS?

Simplification involves writing the fraction in a simpler form. This means that it is an equivalent fraction with a smaller numerator and denominator. For simplifying a fraction, we have tofind a number that can be used to divide the numerator and denominator exactly.

Remember to look for the largest number that can be used to divide!

## Assessment

Learning Outcome 1:Die leerder is in staat om getalle en die verwantskappe daarvan te herken, te beskryf en voor te stel, en om tydens probleemoplossing bevoeg en met selfvertroue te tel, te skat, te bereken en te kontroleer.

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

1.9.2 multiplication of whole numbers to at least 12 x 12.

## Content actions

PDF | EPUB (?)

### What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

PDF | EPUB (?)

### What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

#### Collection to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

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.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks

#### Module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

#### Definition of a lens

##### Lenses

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.

##### What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

##### Who can create a lens?

Any individual member, a community, or a respected organization.

##### What are tags?

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks