1TH/Vwo §8.1 Calculating with numbers

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 1

§8.1 Calculating with numbers

Some new words will come up!

It's important to know their meaning.

That's what this LessonUp is for.

The new words:

brackets           product       quotient

sum             difference                   

Try to take in the following information.

Later in this LessonUp there will be several questions about it!

Sum :

Adding up two (or more) numbers together,

gives us the Sum of the numbers.  Like  35 + 12 = 47

In fact 'the sum' is our 'de som'!

Indeed, awe-sum!

Difference:

When you subtract 2 numbers from each other, 

the result is the Difference.

For example:          45 - 16 = 29,  so 29 is the Difference of 45 and 16.

Product:

Multiplying 2 (or more) numbers by each other,

gives us the Product of the numbers.

Like 23 x 3 = 69, so 69 is the Product of 23 and 3.

Quotient:

When you divide 2 numbers by each other, the result is called the Quotient of them.

For example:  14 : 7 = 2,  so the Quotient of 14 and 7 is 2.

Mention the most important 4 words from the previous slides.

The Product of 15 and 3 is ......

1. 18
2. 5
3. 45
4. 12

The Product of 15 and 3 ....

means the Multiplication of 15 and 3, so:

15 x 3 = 45

The Sum of 34 and 13 is .........

1. 21
2. 21
3. 57
4. 47

The Sum of 34 and 13 is ...

47, because the Sum means Adding!

The quotient of 27 and 9 is ........

What has to do most with arithmetic?

1. Sam
2. Some
3. Sum
4. Somme

Who won the TATA steel chess tournament lately?

Maybe you remember from your old school ..

that x  and  :  go before  +  and   -.

This is still true.

However, there can be exceptions...

See next slide!

Time for ....

Brackets are the New Things!

Amazing stuff, down here:

Amazing stuff, down here:

So, thanks to the Brackets (=haakjes), the old Priority (=voorrang) is changed:

normally -but what is normal in Maths?- we'd do 2 x 5  first,

but because of those Brackets we first do:     8 + 2.

What is the result of:
(6 + 6) : 3 ?

1. 3
2. 4
3. 9
4. -5

Explanation:       (6 + 6) : 3 =

First work out the Brackets:

(6 + 6) : 3 = 12 : 3 =4              (Notice that the Brackets have gone now, as they have no meaning any more. This just between brackets. And between you and me.)

That's why the good answer is 4!

FINALLY:  Try to understand the meaning of the next slide!

In the next slide the meaning is explained!

Here is an example.

Watch how the Calculation is worked out step by step!

The next example is for you to work out and send in in a 'Fotovraag'!

1. Work this task out on paper.

2. take a picture of this and

3. send it in in the next slide!

4. so show us your Calculation and

5. not only the Answer!

I expect everybody to do this Task now. Good luck!

Calculate 7 + 3 x 4 : 6 - 5 = .........

Solution:

Homework time.

§8.1 :   4   t/m   10;   for number 9 don't forget to work out a Calculation! Just like the 2 examples showed you.

(So skip 1, 2 and 3.)

Send in the lot as usual in GC by pics from corrected Homework.