Skip to content Skip to navigation

Connexions

You are here: Home » Content » Compare sizes

Navigation

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? tag icon

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

This content is ...

In these lenses

  • GETSenPhaseMaths display tagshide tags

    This module is included inLens: Siyavula: Mathematics (Gr. 7-9)
    By: Siyavula

    Review Status: In Review

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

    Click the tag icon 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.
 

Compare sizes

Module by: Siyavula Uploaders. E-mail the author

MATHEMATICS

More Geometry, Data Handling and Probability

EDUCATOR SECTION

Memorandum

Table 1
3 cm2 cm10 cm6 cm
6 cm4 cm20 cm24 cm
9 cm6 cm30 cm54 cm
15 cm10 cm50 cm150 cm
3. (a)

(b) 2 twice more; 3 times more;

5 times more than first rectangle

(c) 16 times

4.2.1 – 4.2.4 Check learner’s effort.

LEANER SECTION

Content

ACTIVITY: Compare sizes [LO 4.2, LO 3.8]

3. LET US COMPARE SIZES!

The following rectangle has been enlarged first two times, then three times and then five times.

Figure 1
Figure 1 (graphics1.png)

All the rectangles have the same ratio for length to breadth: 3:2.

a) Look again at the rectangles above. Suppose that each block is 1 cm by 1 cm. Complete the table.

Table 2
Rectangle Length Breadth Perimeter Area
1 __________ __________ __________ __________
2 __________ __________ __________ __________
3 __________ __________ __________ __________
4 __________ __________ __________ __________

b) What happens to the perimeter each time the rectangle is enlarged?

_____________________________________________________________________

_____________________________________________________________________

c) How many times larger is the area if the rectangle is enlarged four times?

_____________________________________________________________________

4.1 Did you know?

The ratio to scale is always written in a specific way:

The first number refers to the drawing/plan.

The second number refers to reality.

A scale of 1:5 means that the length is 5 times smaller than in reality.

A scale of 5:1 means that the length is 5 times bigger than in reality.

4.2.1 Use the graph paper and enlarge the sketch on a scale of 4:1.

Figure 2
Figure 2 (graphics2.png)

4.2.2 Enlarge this drawing on a scale of 1:2.

Figure 3
Figure 3 (graphics3.png)

4.2.3 Reduce this sketch on a scale of 2:1.

Figure 4
Figure 4 (graphics4.png)

4.2.4 BRAINTEASER!

  • Can you enlarge this drawing and re-draw it?
Figure 5
Figure 5 (graphics5.png)

Assessment

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 3.8:We know this when the learner locates positions on co-ordinate systems (ordered grids) and maps

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

Assessment Standard 4.2:We know this when the learner solves problems.

Content actions

Download module as:

PDF | EPUB (?)

What is an EPUB file?

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

Downloading to a reading device

For detailed instructions on how to download this content's EPUB to your specific device, click the "(?)" link.

| More downloads ...

Add 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? tag icon

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