In this lesson we're going to learn finding a quantity when given in percentage. In some question, you need to find the original quantity in percentage that's one we're going to have a look today. Also this also called the unitary method.
1. Our first example is "If 7% of an amount is $56, what is the total amount?"
7% of an amount = $56 We divide by 7 equally.
1% if an amount = $8. Then we multiply by 100 equally.
100% = $800
2. Second example is "Jake spend 25% of his total savings on a new game console which it cost $360. What was his original saving?"
25% = $360 We divide by 25 equally.
1% = 14.4 Then multiply it by 100 equally.
100% = $1440
Showing posts with label Percentage. Show all posts
Showing posts with label Percentage. Show all posts
Friday, October 1, 2010
Thursday, September 30, 2010
Finding the quantity in percentage
In this lesson we're going to learn finding the quantity in percentage. Previously I said percentages uses in our life every day. Sometimes you need to find part of the quantity from the total quantity which is in percentage.
There are 3 methods to find the quantity.
Method 1 is convert percentages to fraction with the denominator of 100 then multiply.
Method 2 is convert the percentage to simplified fraction then multiply.
Method 3 is convert the percentage to decimal then multiply.
1. Our first example is "Find 25% of $500."
There are three methods to find the quantity. It doesn't matter which method you choose the answers are same.
Method 1: 25% = 25/100
i.e 25/100 x 500/1.
= $125.
Method 25% = 1/4 when is simplified.
1/4 x 500/1 = $125
Method 3: 25% = 0.25.
500 500 x 0.05 = 25
x 0.25 500 x 0.20 = 100
25
+ 100
125
Second example is " Find 35% of 50 laptops."
35/100 x 50/1 = 1750/100 = 17.5 = 17 laptops.
OR 0.35 x 50 = 17.5 = 17 laptops.
Third example is 10% of $850."
10/100 x 850 =$85
i.e $85.
Forth example is "Find 33 1/2% of 240."
In this case method 2 much more easier this time.
33 1/2% = 67/200
67/200 x 240 = 402/5 = 80.4.
i.e 80.4.
There are 3 methods to find the quantity.
Method 1 is convert percentages to fraction with the denominator of 100 then multiply.
Method 2 is convert the percentage to simplified fraction then multiply.
Method 3 is convert the percentage to decimal then multiply.
1. Our first example is "Find 25% of $500."
There are three methods to find the quantity. It doesn't matter which method you choose the answers are same.
Method 1: 25% = 25/100
i.e 25/100 x 500/1.
= $125.
Method 25% = 1/4 when is simplified.
1/4 x 500/1 = $125
Method 3: 25% = 0.25.
500 500 x 0.05 = 25
x 0.25 500 x 0.20 = 100
25
+ 100
125
Second example is " Find 35% of 50 laptops."
35/100 x 50/1 = 1750/100 = 17.5 = 17 laptops.
OR 0.35 x 50 = 17.5 = 17 laptops.
Third example is 10% of $850."
10/100 x 850 =$85
i.e $85.
Forth example is "Find 33 1/2% of 240."
In this case method 2 much more easier this time.
33 1/2% = 67/200
67/200 x 240 = 402/5 = 80.4.
i.e 80.4.
Wednesday, September 29, 2010
Conversions you must remember in percentage
The table below is the conversion of percentages to decimal or fraction. This conversions are basic conversions that you must remember.
Percentage | Decimal | Fraction | Simplified fraction |
25% 50% 75% 100% | 0.25 0.50 0.75 1.00 | 25/100 50/100 75/100 100/100 | ¼ ½ ¾ 1 |
20% 40% 60% 80% | 0.2 0.4 0.6 0.8 | 20/100 40/100 60/100 80/100 | 1/5 2/5 3/5 4/5 |
33 1/3% 66 2/3% | 0.3333333333… 0.6666666666… | 33 1/3/100 66 2/3/100 | 1/3 2/3 |
12 ½% 37 ½% 62 ½% 87 ½% | 0.125 0.375 0.625 0.875 | 125/1000 375/1000 625/1000 875/1000 | 1/8 3/8 5/8 7/8 |
Tuesday, September 28, 2010
Changing percentages to decimals, changing decimals to percentage
In this lesson we're going to do another converting lesson. This time is converting percentages to decimal and converting decimals tom percentages.
Converting decimals to percentages or converting percentages to decimals is quite easy to do it.
Firstly to change percentages to decimals:
1. you need to divide the numerator from the denominator.
2. Then move the decimal point to the left twice.
Second is to change decimals to percentage, there are two methods you can choose.
1. Multiply decimal from 100.
2. Move the decimal point to the right, twice.
1. Our first example is "Convert 32% to a decimal."
32% = 32/100.
= 0.32
2. Second example is "Convert 253% as decimal."
253% = 253/100 = 2.53.
3. Third and last example is " Convert 78 1/5% to a decimal."
78 1/5% = 78.20/100 = 0.782.
1. Our first example in converting decimals to percentage is " Convert 0.34 as a percentage."
We move the decimal point to the right, or you do 0.34 multiplied by 100.
0.34 = 34%, 0.34 x 100 = 34%.
2. Second example is "Convert 7.52 to percentage."
Same as this, you move the decimal point to the right or do the multiplication.
7.52 = 752% or 7.52 x 100 = 752%.
3. Third and example is "Convert 0.875 to percentage."
0.875 = 87.5% or 87 1/2% or
0.875 x 100 = 87.5% or 87 1/2%.
4. Forth and last example is "Convert 0.0525 to percentage."
0.0525 = 5.25% or 5 1/4% or
0.0525 x 100 = 5.25% or 5 1/4%.
Converting decimals to percentages or converting percentages to decimals is quite easy to do it.
Firstly to change percentages to decimals:
1. you need to divide the numerator from the denominator.
2. Then move the decimal point to the left twice.
Second is to change decimals to percentage, there are two methods you can choose.
1. Multiply decimal from 100.
2. Move the decimal point to the right, twice.
1. Our first example is "Convert 32% to a decimal."
32% = 32/100.
= 0.32
2. Second example is "Convert 253% as decimal."
253% = 253/100 = 2.53.
3. Third and last example is " Convert 78 1/5% to a decimal."
78 1/5% = 78.20/100 = 0.782.
1. Our first example in converting decimals to percentage is " Convert 0.34 as a percentage."
We move the decimal point to the right, or you do 0.34 multiplied by 100.
0.34 = 34%, 0.34 x 100 = 34%.
2. Second example is "Convert 7.52 to percentage."
Same as this, you move the decimal point to the right or do the multiplication.
7.52 = 752% or 7.52 x 100 = 752%.
3. Third and example is "Convert 0.875 to percentage."
0.875 = 87.5% or 87 1/2% or
0.875 x 100 = 87.5% or 87 1/2%.
4. Forth and last example is "Convert 0.0525 to percentage."
0.0525 = 5.25% or 5 1/4% or
0.0525 x 100 = 5.25% or 5 1/4%.
Sunday, September 26, 2010
Converting fractions to percentage
In this lesson we're going to learn further on converting fractions to percentage.
This lesson will show you where you have to convert fractions into percentage.
Just to keep in mind there are 2 methods to convert fractions into percentages.
1. Multiply with 100/1.
2. Make the denominator 100 by multiplying the number that it can be divided by 100.
1. Our first example is "If a chipmunk scores 6/20 in spelling test, what percentage is this?
You can use one of the methods above.
6 x 5 = 30/20 x 5 = 100
Therefore 30/100 = 3/10 and equals to 30%.
2. Second example is "There are 50 books from overseas. 10 books are from Untied States, 16 books from Germany, and the remainders are from Russia. Change these to percentages.
10 of 50 are from Untied States,
therefore is 20%,
16 of 50 are from Germany,
therefore is 32%.
Lastly we need to find the remainder. To find the remainder you add all the percentages you found then subtract from 100%.
i.e 20% + 32% = 52%
100% - 52% = 48%.
Therefore 48% of the books are from Russia.
4. Forth and last example is " convert 56/200 into percentage."
Firstly we simplify and the equals 7/25,
secondly we times 4 on the numerator and denominator,
therefore the answer is 28/100 or 28%.
This lesson will show you where you have to convert fractions into percentage.
Just to keep in mind there are 2 methods to convert fractions into percentages.
1. Multiply with 100/1.
2. Make the denominator 100 by multiplying the number that it can be divided by 100.
1. Our first example is "If a chipmunk scores 6/20 in spelling test, what percentage is this?
You can use one of the methods above.
6 x 5 = 30/20 x 5 = 100
Therefore 30/100 = 3/10 and equals to 30%.
2. Second example is "There are 50 books from overseas. 10 books are from Untied States, 16 books from Germany, and the remainders are from Russia. Change these to percentages.
10 of 50 are from Untied States,
therefore is 20%,
16 of 50 are from Germany,
therefore is 32%.
Lastly we need to find the remainder. To find the remainder you add all the percentages you found then subtract from 100%.
i.e 20% + 32% = 52%
100% - 52% = 48%.
Therefore 48% of the books are from Russia.
4. Forth and last example is " convert 56/200 into percentage."
Firstly we simplify and the equals 7/25,
secondly we times 4 on the numerator and denominator,
therefore the answer is 28/100 or 28%.
Changing fractions to percentages
In this lesson we're going to learn converting fractions to percentages.
Converting fractions to percentages are important as converting percentages to fractions.
There's an simple way to convert fractions to percentage.
to convert any fractions into percentage, multiply the fractions by 100% / 1.
1. Our first example is " Convert 12/20 to a percentage."
12/20 x 100/1. We multiply 12/20 by 100% /1.
12/20 x 100/1 Before we multiply,
= 12/1 x 5/1 we find is there any number that it can be simplified.
= 60/1 we found 20 and 100.
i.e 60%. 100 can be divided by 20 therefore 100 divided by 20 is 5.
2. Second example is " Express 4/5 as a percentage."
In this example I'm going to show you another method to convert fractions to percentages.
We know that 5 times 20 equals 100 so we times 20 on numerator and denominator.
4 x 20 / 5 x 20 = 80/100 = 80%.
Therefore the answer is 80%.
3. Third and last example is " Express 5 2/3 as a percentage."
We multiply with 100% /1 this time.
5 /2/3 x 100/1 = 17/3 x 100/1 = 1700/3 = 566%.
Therefore the answer is 566%.
*If you're doing the same method on example 2, make sure that the denominator must be 100.
Converting fractions to percentages are important as converting percentages to fractions.
There's an simple way to convert fractions to percentage.
to convert any fractions into percentage, multiply the fractions by 100% / 1.
1. Our first example is " Convert 12/20 to a percentage."
12/20 x 100/1. We multiply 12/20 by 100% /1.
12/20 x 100/1 Before we multiply,
= 12/1 x 5/1 we find is there any number that it can be simplified.
= 60/1 we found 20 and 100.
i.e 60%. 100 can be divided by 20 therefore 100 divided by 20 is 5.
2. Second example is " Express 4/5 as a percentage."
In this example I'm going to show you another method to convert fractions to percentages.
We know that 5 times 20 equals 100 so we times 20 on numerator and denominator.
4 x 20 / 5 x 20 = 80/100 = 80%.
Therefore the answer is 80%.
3. Third and last example is " Express 5 2/3 as a percentage."
We multiply with 100% /1 this time.
5 /2/3 x 100/1 = 17/3 x 100/1 = 1700/3 = 566%.
Therefore the answer is 566%.
*If you're doing the same method on example 2, make sure that the denominator must be 100.
Converting percentages as fractions,
In this lesson we're going to learn converting percentages to fractions. I assume you guys are now confident with the converting so this lesson will be an easy one.
Converting percentages to fraction is easy. reason we learned that the meaning of the percentage is hundredth or out of 100. Also when you changed to fractions, some of the fractions can be simplified.
1. Our first example is "Convert 60% to fractions."
To review our work, percentage is one of special fraction,
which it has a denominator of 100.
So 60% can be written in 60/100 and we simplify and the answer is 3/5.
2. Second example is "Convert 25% to a fraction."
25% can be written in 25/100, then simplify therefore our answer is 1/4.
3. third example is 4 1/5% to a fraction."
4 1/5% = 4 1/5 / 100 The numerator and denominator of a fraction must be whole numbers.
= 4 1/5 x 5 / 100 x 5 To make 4 1/5 a whole number, we change it to the improper fraction
= 21/500 then multiply it by 5, same as the denominator, we multiply 100 by 5.
i.e 21/500.
Converting percentages to fraction is easy. reason we learned that the meaning of the percentage is hundredth or out of 100. Also when you changed to fractions, some of the fractions can be simplified.
1. Our first example is "Convert 60% to fractions."
To review our work, percentage is one of special fraction,
which it has a denominator of 100.
So 60% can be written in 60/100 and we simplify and the answer is 3/5.
2. Second example is "Convert 25% to a fraction."
25% can be written in 25/100, then simplify therefore our answer is 1/4.
3. third example is 4 1/5% to a fraction."
4 1/5% = 4 1/5 / 100 The numerator and denominator of a fraction must be whole numbers.
= 4 1/5 x 5 / 100 x 5 To make 4 1/5 a whole number, we change it to the improper fraction
= 21/500 then multiply it by 5, same as the denominator, we multiply 100 by 5.
i.e 21/500.
One whole of percentage
In this lesson we're going to look at some particular questions that is about percentages.
Keep in mind when you're doing a question about percentage, it must be add up to 100%.
Previously I told you in percentage, percentage means hundredth or out of 100. Unfortunately I have to say the best solution to understand is working through these examples below.
1. First example is "I scored 88% in maths test. What percentage have I got wrong?"
We know that 88% is correct, we subtract 88% from 100%.
Therefore the answer is 12%.
2. Second example is "A company consist 60% of females. What percentages are male?"
We know that 60% is female, so we subtract 60% from 100%.
Therefore the answer is 40%.
3. Third example is A class has 3 choice of sport in this term: tennis, swimming or shooting.
32% of the student choose to play swimming and 47% to do shooting. What percentage of the student will be playing tennis?
Swimming + shooting = 32% + 47% = 79%
Total percentages must add up to 100%.
So, we subtract 79% from 100%.
Therefore the answer is 21%.
4. Forth and last example is "Jon got 56%, 23% and 98% in 3 separate history exams. What was his average marks?"
When you're finding average you have to add all the scores and divide by the number of the scores.
Average = 56% + 23%+ 98% / 3.
Therefore the answer is 177/3 = 59
i.e 59%.
* Another way to say the average is mean.
Keep in mind when you're doing a question about percentage, it must be add up to 100%.
Previously I told you in percentage, percentage means hundredth or out of 100. Unfortunately I have to say the best solution to understand is working through these examples below.
1. First example is "I scored 88% in maths test. What percentage have I got wrong?"
We know that 88% is correct, we subtract 88% from 100%.
Therefore the answer is 12%.
2. Second example is "A company consist 60% of females. What percentages are male?"
We know that 60% is female, so we subtract 60% from 100%.
Therefore the answer is 40%.
3. Third example is A class has 3 choice of sport in this term: tennis, swimming or shooting.
32% of the student choose to play swimming and 47% to do shooting. What percentage of the student will be playing tennis?
Swimming + shooting = 32% + 47% = 79%
Total percentages must add up to 100%.
So, we subtract 79% from 100%.
Therefore the answer is 21%.
4. Forth and last example is "Jon got 56%, 23% and 98% in 3 separate history exams. What was his average marks?"
When you're finding average you have to add all the scores and divide by the number of the scores.
Average = 56% + 23%+ 98% / 3.
Therefore the answer is 177/3 = 59
i.e 59%.
* Another way to say the average is mean.
Saturday, September 25, 2010
Percentage introduction
In this lesson we're starting a new chapter percentage. Percentage uses in our life daily and is another special fraction which has denominator of 100.
Percentage occurs everyday in our life. For example your exam mark comes out in percentages, your school report comes out in percentages and statistics on population.
Percent can be written as %.
It means hundredth, or out of 100 or per hundred and % is made by the two zeroes,
therefore that's why the percentage means hundredth or out of 100, or per hundred.
For example if there are 100 squares and 34 of them are shaded, find the percentage of the squares that has been shaded.
We write the total in denominator and in numerator, write the number of the square which are shaded.
Therefore the answer is 34/100 or 34% or 34 out of 100 or 34 hundredth.
Percentage occurs everyday in our life. For example your exam mark comes out in percentages, your school report comes out in percentages and statistics on population.
Percent can be written as %.
It means hundredth, or out of 100 or per hundred and % is made by the two zeroes,
therefore that's why the percentage means hundredth or out of 100, or per hundred.
For example if there are 100 squares and 34 of them are shaded, find the percentage of the squares that has been shaded.
We write the total in denominator and in numerator, write the number of the square which are shaded.
Therefore the answer is 34/100 or 34% or 34 out of 100 or 34 hundredth.
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