# Multiplication

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## To be able to use a series of techniques to do calculations [lo 1.10.5]

By now you know how to multiply by smaller numbers. Now we are going to see whether you are also able to do calculations with bigger numbers. Split up into groups of 3 and ask your teacher to give you the paper you need. Then read the instructions very carefully.

Michaela and her friends visited the zoo and heard the following interesting facts: a hippopotamus eats 45 kg of fodder per day, while a large bull elephant needs 225 kg of fodder per day!

1. How many kilograms of fodder will 329 hippopotamuses eat per day?

2. How many kilograms of fodder must the zoo buy per day to feed 76 bull elephants?

3. If the entrance fee was R15 per person and 475 people visited the zoo that day, how much money was taken at the entrance gate?

4. Explain to the rest of the class how your group calculated the answers.

5. Compare your methods. How do the various methods differ from each other?

6. Use a pocket calculator to check the answers.

## To use strategies to check solutions [lo 1.11]

1. In the previous activity you probably noticed that there is more than one method to do multiplication. Split up into groups of 3 again. Look carefully at the solutions to the following problem and explain the methods to one another.

Mrs Cele sells clothes. There are 46 different pairs of jeans and 238 different shirts. How many combinations can she make up?

1.1 I calculate 46 × 238 in this way

238 × 46 = (200 + 30 + 8) × (40 + 6)

200 × 40 = 8 000

30 × 40 = 1 200

8 × 40 = 320

200 × 6 = 1 200

30 × 6 = 180

8 × 6 = 48

10 948

1.2 I write it in this way:

238

× 46

48 (8 × 6)

180 (30 × 6)

1 200 (200 × 6)

320 (40 × 8)

1 200 (40 × 30)

8 000 (40 × 200)

10 948

1.3 My method looks like this:

2 2 4 3 8

× 4 6

1 4 2 8

9 5 2 0

1 0 9 4 8

2. Now use any method that you understand and with which you feel comfortable, and calculate the product of:

2.1 576 × 47

2.1 576 × 47

CHALLENGE!

Can you calculate the product of the following by using the method shown in 1.3?

1. 347 × 251

2. 526 × 438

ANOTHER BRAIN-TEASER

Study the following sum carefully: 24 × 13 = 377

One of the digits is incorrect. Can you find out which one it is? ..............

What must it be? .........................

## To solve problems in context [lo 1.6.1]

Let’s go out to dinner.

This assignment is for your portfolio. Your teacher will go through it with you and explain exactly what you are expected to do. Make sure that you understand perfectly before you start. Remember to work neatly.

Form groups of three. Your group decides to eat something from each section of the menu. To make it easier for the waiter, each person in your group chooses the same soup, starter, main course and dessert.

Decide what you are going to order and then calculate your account. Use the block below. You may use a calculator. First estimate what the meal will cost the group. ..............................

where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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