Math Games

You can play some games in these links. Enjoy MATHS!

http://ababasoft.com/kids/index_math.html

http://www.gamequarium.com/math.htm

Addition

Addition has always been simple. But imagine if add some seven 5-digit  numbers in your head and tell the answer in just a second.

Lesson 1:


So lets consider a list of one digit numbers:
5
7
6
9
8
3
1

"Now you can add the numbers easily." This is the best tool for mental arithmetic.Feel easy. The world will feel that you are the best.Now don't get irritated.I just wanted to tell, Find out the set of two numbers that add to 10. Then the number of sets would correspond to 10's. That is in this example you can keep sets of 9and1 then 7and3. So there are two sets. So keep 20. Then add the balance numbers and add them to the 20. The answer would be 39 then.

The answer is : 39

Lesson 2: Tacking up

Here comes the main part. Without learning the next part quick multiplication would be difficult.
                                46
                                59
                                94

1.Now add the first column of numbers.
you get 18
2. Keep this in mind. Now add the second column. You get 19.
3. Now add the tenth digit of 19, that is 1 to 18 and then simply attach the 9. You get 199.

"This method of adding the digits with respective to zeroes present and then simply attaching the once digit is called Tacking up."

Now if it was:
                             406
                             509
                             904
 The same sums would come. That is 18 and 19.
 But the sum would be 1819. But since zero is in middle. Then the tenth digit also would be tacked up.
But if it was a three digit then the hundredth digit would be added up and the remaining two digits would be tacked up.

You know why the left to right addition helps? It would be helping you in mental arithmetic When a list of numbers are given or when you are asked to square a number and also in many methods which you will learn.

Now use this method for adding three digit numbers also.

Lesson 3: Three digit addition

                                        576
                                        487
                                        832

 The sum would be 17 18 15.
So if you tack up then the sum would be 1895.

Lesson 4:
Arithmetic progression:

Say if a series of numbers starts With some 21 and ends with 29.
That is:                             21
                                        22
                                        23
                                        24
                                        25
                                        26
                                        27
                                        28
                                        29

 Find the middle number or find out the average. Here it is 24.5and see how many numbers are there. Here it is 10. Multiply 10 with 24.5. The answer is 245 that is the sum of the series.

Percentage

Calculating percentages: Percentages are interesting to calculate. We convert the multiplication into addition. That's it.

Just consider numbers 1, 2, 5, 10, 20, 50,100. Can you see anything? Yes they are the denominations of Indian currency. These are enough to calculate any percentage values directly.

for 1%: divide the given number by 100.
for 10%: divide the given number by 10.
for 100%: It is the actual given number.

for 2%: divide the given number 100 and multiply by 2 or just divide the given number by 5 and then divide by 100.
for 20%: divide the given number 10 and multiply by 2 or just divide the given number by 5 and then divide by 10.
for 200%: It is the actual given number multiplied by 2.

for 5%: divide the given number 100 and multiply by 5 or just divide the given number by 2 and then divide by 100.
for 50%: divide the given number 10 and multiply by 5 or just divide the given number by 2 and then 10.
for 500%: It is the actual given number  multiplied by 5.

For your number: 25.6% of 488

26.5 = 25 + 1 +.5

25% of 488 = 488/4 = 122.[Because 488 * 25/100 => 488*1/4]

1% of 488 = 488/100= 4.88

.5% of 488 = 488/200 = 2.44

Now add all the values.It gives 129.32 which is the answer. If you wanna calculate 3% find 1% and multiply it by 3. If you wanna calculate 7% calculate 5% and add 2%. That's it.