The first arithmetic topic that will be dealt with here is Time and Distance along with Unitary method.
Later principles of BODMAS will be taken up.
Another important topic that will be looked into is Time and Work.

Thursday, March 28, 2013

Time and Distance - 2

In what time will a train, 125 m long, moving at a speed of 45 kilometres per hour, cross a bridge 265 metres long ?

Solution: To cross a bridge, a train has to travel a distance equal to the sum of its own length and the length of the bridge. So here the train will have to travel (125 m + 265 m) = 390 m.

Now, the speed of the train is 45 Km per hour.
That is, the train covers 45 Km in 1 hour (= 60 minutes).

1 Km = 1000 metres

So, the train covers (45 x 1000) metres in 60 minutes.

therefore, the train covers 1 metre in 60 / (45 x 1000) minutes.

So the train covers 390 metres in 60 x 390 / (45 x 1000) = 52 /100 minutes.

1 minute = 60 seconds.

By multiplying minutes by 60 we gets seconds.
So 52/100 minutes = 52 x 60 / 100 seconds = 312/ 10 seconds = 31.2 seconds.

Answer: The train crosses the bridge in 31.2 seconds.

Sunday, March 24, 2013

What is Arithmetic

Arithmetic is the oldest and most elementary branch of mathematics. It is used by everyone to carry on with their day-to-day operations. Higher up it is used for scientific and business calculations. Arithmetic is to mathematics what letter is to a word. Arithmetic is the basic foundation of mathematics.

The two basic arithmetic operations are addition (+) and subtraction (-).  In its simplest form, addition combines two numbers into one. Subtraction finds the difference between two numbers. The difference can be either, positive, negative or zero.

From addition we can derive another operation called multiplication (× or *), which is nothing but repeated addition of the same number to another.

From subtraction we can derive another operation called division (÷ or /), which is nothing but repeated subtraction of the same number from another.

Arithmetic clears the logical thinking ability of our brain and makes it more and more analytical in its thinking prowess. Logic is concerned with the principles of correct reasoning, and it is the study of arithmetic which vastly improves our reasoning ability. 

A student, in his/her infancy, begins his/her study of mathematics with positive numbers and arithmetic. Arithmetic deals with natural numbers, integers, fractions, and decimals, which the student learns in course of time. In later stages a student learns how to solve basic problems using the various tools provided by arithmetic and logic.