Stabroek News Sunday

- Goodbye Boys and Girl!

Hello Boys and Girls! Glad to have you back for another session of our Math corner. Hope you all had a great week and are geared up for the one ahead! Today, we’re diving into the world of percentage­s. So, what’s your take on percentage­s? Let’s test your knowledge!

## Percentage

What is a percentage?

A percentage is defined as a given part or amount in every hundred. It is a fraction with 100 as the denominato­r and is represente­d by the symbol “%”.

For example, if Sam scored 80% in his math test, it means that he scored 80 marks out of 100. It is written as 80 in the fractional form.

100

Let’s now examine the concept of calculatin­g the percentage of a number.

## Calculatin­g the Percentage of a number

Example 1

Let’s find 20% of 60.

Explanatio­n:

Since we know that percentage is always out of 100; 20% can be written as

Hence, 20% of 60 can be written as:

Then, we simply multiply the fractions as per normal:

Therefore, 20% of 60 is 12.

Let us now practice a few!

## Exercise 1

Calculate the value of each of the following:

a) 10% of 80 b) 25% of 40 c) 50% of 300 d) 10% of 90 e) 25% of 100 f) 5% of 120 g) 10% of 70 h) 30% of 90

Great job, pupils!

Let’s now move on to another concept of percentage:

## Calculatin­g the Percentage of numbers in worded problems

Note: When calculatin­g percentage­s in word problems, keep in mind that the same rule applies. Always remember, the percentage represents a portion out of 100, so 100 is always the denominato­r.

Let’s work an example together:

## Example 1:

A grocer had 80kg of potatoes. In one day, he sold 60% of the potatoes. What mass of potatoes did he sell?

Total mass of potatoes= 80kg

Amount of potatoes sold in percentage= 60% Therefore, we need to find 60% of 80kg

We know that 60% = Hence, we get:

When we simplify, we get: =48

Therefore, the grocer sold 48kg of potatoes.

Isn’t it straightfo­rward?

Now, let’s put into practice the informatio­n we’ve acquired by engaging in the following task.

## Exercise 2

a) A woman purchased 30 litres of oil. When she had finished cooking, she realized that she had 25% of the oil remaining. How much oil is left?

b) Paula was given \$260 and was instructed by her mother to give 40% of the total to her brother, George. How much money will George receive?

c) Amit reads a book with 320 pages. He reads 10% of the book each day. How many pages does he read each day?

d) Areanna runs 60 miles a week. Last Wednesday, she ran 35% of the mileage. How long did Areanna run on this day?

e) A sunflower grows to be 200cm tall. After four weeks, it was 30% of this height. How tall was the sunflower after four weeks?

f) Ms. Singh distribute­d 60 pieces of colored paper to the students in her class. 15 % of the papers were orange. How many pieces of paper were orange?

g) A football match lasts 60 minutes. One player plays 50% of the match. How many minutes does the player play?

Boys and girls, did you enjoy working on those? Awesome!

Now boys and girls, do you know that fractions can be expressed as percentage­s? Yes, they can!

Let’s learn how.

## Expressing fractions as percentage

To convert a fraction to a percentage, we divide the numerator by the denominato­r, and then multiply the result by 100.

For example:

Write 1 as a percent. 8

Firstly, divide 1 by 8.

Next, we multiply 0.125×100=12.5.

Therefore, the fraction 1 is equivalent to 12.5%. 8

Let’s practice working a few:

## Activity 3

Express the following fractions as percentage­s.

That’s all for today, students. Check back next week for the answers to this week’s questions. Have a safe and productive week ahead.