PERCENTAGE (Lessons 1 & 2)

FOCUS QUESTION
How can I represent shared portions?

SPECIFIC OBJECTIVE
1.Tell what percentage of a set or object is shown,

2. Write a percentage as fraction with a denominator of 100, or, in its simplest form and/or as   a decimal

3. Reconize that 100% is a whole

4. calculate a given percentage of a number, amount of money, measure of mass, etc.

5. Solve  problems requiring the conversion of fractions to percentage and vice-versa

 
CONTENT SUMMARY

ENGAGE

Children, today we will be looking at a new concept in Mathematics. I want you to try to figure it out. It means per hundred or out of a hundred. What do you think it is?

                                               PCATEREGNE

Now examine the grid below. It represents a Hundred Grid. The entire grid represents 100% or 1 whole. If  I shade 1 square, I would have shaded 1% or 1/100. Suppose I shade half of the square, what fraction would I have shaded ? What percentage is this?

Shade 1/4 and 3/4 and tell me the percentage amount for each of these.

EXPLORE

Now I want you to shade the given percentages on the charts below.

Now sometimes you may be asked to find the percentage of figures that do not have 100 squares. How would we determine the percentage? 

Let's look at the chart below. Look at the bottom exercise.

Yo will recall how to determine what part of a figure is shaded. (By putting the shaded part over the number of parts the shape is divided in.

For example, 1/10 of the first figure is shaded. We can simply multiply the 1/10 by 100 and that will give us 10%.

Sometimes we may be asked to find out the percentages of different quantities. Let us look at the problem below.

What is 5% of 600. There are a number of methods that could be used to solve this problem. Let us look at each.

METHOD 1

NB Please note that 5% = 5/100=1/20 in its lowest term.

Things to always remember.

1/4= 25%

1/2 = 50%

3/4=75%

EXPLAIN

What is meant by percentage?

Explain how you find the percentage of a number.

How can a fraction be written as a percentage?

EXTEND/ELABORATE

Can you think of another method that could be used to solve the same problem in question?

METHOD 3

5 % of 600

5 % = 0.05 (5 hundredths)

since "of " stands for multiply then multiply 0.05 x 600

      0.05  (2 decimal places in factor)

    x 600  (no decimal place)

  30 . 00   ( 2 decimal places)

N.B. Always remember then when multiplying decimals, the number of decimal places in the product should be equal to the number of decimal places in the factors)

Try to solve the following using any two methods.

1. 10% of 50

2. 30% of 200

EVALUATE

Task 1.

Write the following as percentages.

(a) 2/5     (b) 8/10    (c) 4/8 

Task 2

Write the following as decimals.

(a) 45/100    (b) 6%    (c) 9/100

Task 3.

(a) What is   20% of 1000.

(b) Susan had 300 stamps. She gave away 5%. How many did she give away? How many she had left?

(c) There are 200 children at a camp. 70% of them are boys. How many of the children are girls?

     (i) 140   (ii) 130    (iii) 60   (iv) 30

Task 4

Percent	Fraction	Decimal
85%
	5/10
		0.65
6 %
	7/10

Task 5

Click on the link below to complete the task below by typing in the correct answers.


Percentages