<< Chapter < Page Chapter >> Page >

Mathematics

Multiplication

Educator section

Memorandum

1.1 9 x 25 ÷9 x 100) ÷ 4

1.2 368 x 25 ÷368 x 100) ÷ 4

1.3 16 x 25 ÷16 x 100) ÷ 4

2. 2.1 ÷324 x 100) ÷ 4

32 400 ÷ 4

8 100

2.2 ÷1 436 x 100) ÷ 4

143 600 ÷ 4

35 900

2.3 ÷26 844 x 100) ÷ 4

2 684 400 ÷ 4

671 100

Brain teasers

yes

÷1 436 ÷ 4) x 100

359 x 100

35 900

3.1

375
625
1 125

3.2

3 000 _______ 375
5 000 _______ 625
9 000 _______ 1 125

4. Answer the same.

5. 1 000

8

divide

8

1 000

multiplication

6.1 36 x 1 000 1 056 000 ÷ 8

36 000 132 000

6.2 132 x 1 000 ÷1 056 x 1 000 ÷ 8

132 000 132 000

Brain teasers

x 1 000  2 / x 5 x 100 / 2 x 1 000

Leaner section

Content

Activity: to use a range of techniques to perform calculations [lo 1.10.3]

To determine output values for given input values [lo 2.3.3]

It is very important to develop strategies for arriving at answers quickly to make life easier in Grade 6. Let us take a look at some bright ideas to use when we do multiplication!

REMEMBER!

When you multiply by 25 you can first multiply by 100 and

then divide by 4!

1. Can you balance the following scales by filling in the correct number?

1.1

1.2

1.3

2. Use the above method to calculate:

2.1 324 x 25 =

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

2.2 1 436 x 25 =

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

2.3 26 844 x 25 =

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

BRAIN-TEASER!

Can I also first divide by 4 and then multiply by 100? _________________________

Prove your answer!

1 436 x 25 =_____________________________________

=___________________________________________

=___________________________________________

3. Look carefully at the following example and then complete the tables:

3.1 1 × 125 125
3 × 125 _____
5 × 125 _____
9 × 125 _____
3.2 1 × 1 000 1 000 ÷ 8 25
3 × 1 000 _____ ÷ 8 _____
5 × 1 000 _____  8 _____
9 × 1 000 _____  4 _____

4. Compare the answers in the tables. What do you realise?

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

5. Complete the following:

REMEMBER:

If I have to multiply by 125 I can first multiply by ____________________________

and then __________________ the answer I get by ___________________________

OR I can first divide the number by_________________________________ and then

____________________________ the answer by _____________________________

6. See if you can apply this method!

6.1 288 x 125 = ÷288  8) x 1 000

= _______________________

= _______________________

or

288 x 125 = ÷288 x 1 000) ÷ 8

= _______________________

= _______________________

6.2 1 056 x 125 = ÷1 056 ÷ 8) x 1 000 or _____________________

= _______________________

= _______________________

BRAIN-TEASER!

WITHOUT using a calculator, how would you multiply a number by 500 in two seconds?

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 1.10: We know this when the learner uses a range of techniques to perform written and mental calculations with whole numbers including:

1.10.3: building up and breaking down numbers.

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 2.3: We know this when the learner determines output values for given input values, or input values for given output values, using:

2.3.3: tables.

Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
Aislinn Reply
cm
tijani
what is titration
John Reply
what is physics
Siyaka Reply
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Jude Reply
Can you compute that for me. Ty
Jude
what is the dimension formula of energy?
David Reply
what is viscosity?
David
what is inorganic
emma Reply
what is chemistry
Youesf Reply
what is inorganic
emma
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
Krampah Reply
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
Sahid Reply
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Joseph Reply
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
Ryan
what's motion
Maurice Reply
what are the types of wave
Maurice
answer
Magreth
progressive wave
Magreth
hello friend how are you
Muhammad Reply
fine, how about you?
Mohammed
hi
Mujahid
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
yasuo Reply
Who can show me the full solution in this problem?
Reofrir Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Mathematics grade 6. OpenStax CNX. Sep 10, 2009 Download for free at http://cnx.org/content/col11030/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Mathematics grade 6' conversation and receive update notifications?

Ask