Showing posts with label percents. Show all posts
Showing posts with label percents. Show all posts

Monday, 20 February 2012

Percents problems in mathematics

In today’s free math problem solver session we are going to discuss how to solve percent problems in mathematics. This is the very important part of mathematics. Most of the problems are based on the percentage. Here we will discuss about such problems related to Grade IV.
We generally face percents problems which are chiefly of three types: (for more detail read this)
1. Missing Percent Problems: In such problems the task is to find what percent one quantity is of the other quantity.
2. Missing Part Problem: In this kind of problems we need to find what quantity is given percent of other quantity.
3. Missing Whole Problem: In this kind of problems we find the full or whole quantity given what percent a certain quantity is, like the 100%.
In the above mentioned problems the 3rd problem is difficult.
If we need to find 15% of 150, we generally first convert the 15% to its compatible decimal form i.e. 0.15. Now 15% of 150 indicate us to multiply the 0.15 and 150, and then we will get 0.15*150 = 22.5. That means 22.5 is the 15th percent of the 150.
Now here is some examples related to the percents problems:
a. What percent of 20 is 25%?
We first have the original number 20 with the comparative number 25. Now we need to find the rate or the percentage. So let the percentage be x.
     25 = x * 20
     25/20 = x
     x = 1.25
Now the task is to convert this decimal back into the percentage: 1.25 = 125%
Now we can say that 25 is the 125% of 20.
b. What is 35% of 50?
X = 0.35 * 50 (here x stands for a number)
X = 17.5
Now the 17.5 is 35% of 50.
So today we learnt about the percents problem.

In upcoming posts we will discuss about Addition and subtraction and Powers and repeated multiplication in Grade V. Visit our website for information on CBSE political science board paper

Sunday, 8 January 2012

Fractions and Decimals in Grade IV

Hello friends, now we are going to learn about some of the chapters of mathematics for grade IV. Today we wil learn about decimals (read how to divide decimals), fractions and percents of the numbers. We will get introduced by composition and decomposition of numbers also.
First introducing with fraction and decimals. Fractions are the numbers which represent the part of a whole number. These are in the form of ratio of numerator to denominator. For example 3/4, 5/6, 2/3 etc. Just taking 5/6 in the consideration, then 5 is the numerator which tells us that the fraction represents 5 equal parts, and the denominator, 6, tells us that 6 parts equals a whole quantity. Fraction number shows the part of a whole number and they are used to represent some ratio and decimal form of numbers. Just like fraction, decimal is the number which also shows some part of the whole number. Decimal numbers are the types of fraction of a whole number and they also come from the fraction number. 
For example any fraction number can be converted into the decimal number and decimal also can be same. Say for example any fractional number is ½ then by simplifying it we can write it as 0.5. The simplification is as that let us multiply by 5 on both numerator and denominator terms and we gets 5/10 which on decomposing in the decimal becomes 0.5. So ½ is equivalent to the 0.5 which is half of any whole number.
Now discussing about percentage of a Number. Percentage is a way of representation of any number as a fraction of 100(per cent stands for per 100). It is denoted by “%” sign, for example 54 %( also read as “fifty four percent”) which is equal to 54/100 in the fraction and 0.54 in decimal. Percentages are used to show the quantity of any number that how large or small quantity is and the decrease & increase in the price. We have to find percentage of any number in this topic.
For example, 10% of 50 is 5 and this can be calculated by some methods. That is:
                10 / 100 * 50         = 10 * 50 / 100
                                                =  5.
The change in quantity is also represented in percentage in the form of how much the change has been detected in the quantity. So we first need to find the fraction of number and then convert that to the percentage. For example, an increase of $0.10 in money value of $ 2.75 is an increase by a fraction of 0.10/2.75 = 0.036. Expressed as a percentage, this is therefore increase of 3% in the money value. The concept of percentage is also applicable on percentage of a number, discounts, taxes, sales  percent of changes, and percent of comparison.
Compose and decompose numbers is also a topic in some of the real life topics. Compose and decompose numbers stands for breaking any number into as many combinations of groups as possible. Let's say 4 can be composed in four groups of one, two groups of three, a group of four or by many more other combinations.

In upcoming posts we will discuss about Number Operations in Grade IV and Problem solving strategies. Visit our website for information on CBSE board home science syllabus for class 11