1Tvwo §11.2 Multiplication

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

Ch 11 Calculating with variables

Today we will do:

§ 11.2 Multiplication

so:   x (times)

§11.2 Multiplication - a recap:

-  when ADDING we talk about TERMS:  2a +  4b = d    

    here 2a and 4b are the TERMS that you add together

-  when MULTIPLYING we talk about FACTORS:  

    5 x 6 = 30         

 here 5 and 6 are FACTORS, so numbers that are multiplied.

   Or      6f  x  7f = g      here 6f and 7f are the FACTORS that you multiply;

    How?  This you'll learn in this paragraph!

   

Task : What MISTAKE has been made here?!

Think about it.

2a + 5 = p
Here 2a and 5 are ...

1. factors
2. terms
3. numbers
4. variables

2a + 5 = p

SOLUTION:

2a and 5 are the TERMS,

because they are ADDED together.

4 - 7c = h
This is a(n) ....

1. formula
2. calculation
3. equation

4 - 7c = h

SOLUTION:

This is a FORMULA:

It contains 2 Variables. 

When you fill in a number for c, you can calculate h.

7 - 5c -3 + 2c =.....

1. -4 - 2c
2. 4 + 7c
3. 4 - 3c
4. 10 -3c

Do 10a+b in your Notebook:

SOLUTION:

Do 10c in your Notebook now.

SOLUTION:

6f x 5f = ...

1. 30f
2. 11f
3. 11f​2​​
4. 30f​2​​

SOLUTION:

                                                         

                                   6f x 5f = 

30f​2​​

Calculate the AREA of a RECTANGLE with these measurements:
-6 p and -4.1 p

1. −24.6p​2​​
2. 24.6p​2​​
3. −10.1p
4. −10.1p​2​​

SOLUTION

x                     = 

−6p​​​

−4.1p​​​

24.6p​2​​

Task: Try to find both formulas!

Think hard about the answers!

Solution: A:   l x w = Area, so 5p x 3p = 15 

B:  A triangle is only half of a rectangle!  So we get:  3     x  4     x        =  6     

               

​2​​1​​

p​2​​

p​2​​

p

p

Homework time.

Do §11.2 Multiplication (start with exercise 11)