Mathematics
Decimal And Percentage
A group of related sciences, including algebra, geometry, and calculus, concerned with the study of number, quantity, shape, and space and their interrelationships by using a specialized notation
Decimal And Percentage
Decimals
The Concept of Decimals
Explain the concept of decimals
A decimal- is defined as a number which consist of two parts separated by a point.The parts are whole number part and fractional part
Example 51
Example 52
Conversion of Fractions to Terminating Decimals and Vice Versa
Convert fractions to terminating decimals and vice versa
The first place after the decimal point is called tenths.The second place after the decimal point is called hundredths e.t.c
Consider the decimal number 8.152
NOTE
- To convert a fraction into decimal, divide the numerator by denominator
- To convert a decimal into fraction, write the digits after the decimal point as tenths, or hundredths or thousandths depending on the number of decimal places.
Example 53
Convert the following fractions into decimals
Solution
Divide the numerator by denominator
Operations and Decimals
Addition of Decimals
Add decimals
Example 54
Evaluate
Solution
Subtraction of Decimals
Subtract decimals
Example 55
Solution
Multiplication of Decimals
Multiply decimals
Example 56
Solution
Mixed Operations with Decimals
Perform mixed operations with decimals
Example 57
Solution
Word Problems Involving Decimals
Solve word problems involving decimals
Example 58
If 58 out of 100 students in a school are boys, then write a decimal for the part of the school that consists of boys.
Solution
We can write a fraction and a decimal for the part of the school that consists of boys.
| fraction | decimal |
| 58/100 | 0.58 |
Percentages
Expressing a Quantity as a Percentage
Express a quantity as a percentage
The percentage of a quantity is found by converting the percentage to a fraction or decimal and then multiply it by the quantity.
Example 59
NOTE:The concept of percentage of a quantity can be used to solve the problems involving percentage increase and decrease as shown in the below examples:-
A Fractions into Percentage and Vice Versa
Convert a fraction into percentage and vice versa
To change a fraction or a decimal into a percentage, multiply it by 100%
Example 60
Convert the following fractions into percentages
A Decimal into Percentage and Vice Versa
Convert a decimal into percentage and vice versa
To change a percentage into a fraction or a decimal, divide it by 100%
Example 61
Convert the following percentages into decimals
Percentages in Daily Life
Apply percentages in daily life
Example 62
In an assignment, Regina scored 9 marks out of 12. Express this as a percentage
Solution
Example 63
A school has 400 students of which 250 are girls. What percentage of the students are not girls?
Solution
Listening to this topic
