steps to find square of numbers in 200's
> Choose a number in the 200s (start with numbers under 210, then try for larger ones).
>The first digit of the square is 4: 4 _ _ _ _
> The next two digits will be 4 times the last 2 digits: _ X X _ _
> The last two places will be the square of the last digit: _ _ _ X X
here we take an Example:
> let the number be 207:
> The first digit is 4
so 4 _ _ _ _
> The next two digits are 4 times the last digit:
4 × 7 = 28
so _ 2 8 _ _
Square the last digit: 7× 7 = 49
so _ _ _ 49
So finally we get 206 × 206 = 42849.
and For larger numbers work right to left:
> Square the last two digits (keep the carry): _ _ _ X X
> 4 times the last two digits + carry: _ X X _ _
> Square the first digit + carry: X _ _ _ _
example
>If the number to be squared is 225:
> Square last two digits (keep carry):
25x25 = 625 (keep 6): _ _ _ 2 5
> 4 times the last two digits + carry:
4x25 = 100; 100+6 = 106 (keep 1): _ 0 6 _ _
> Square the first digit + carry:
2x2 = 4; 4+1 = 5: 5 _ _ _ _
> So 225 × 225 = 50625.
Showing posts with label FUN WITH NUMBERS. Show all posts
Showing posts with label FUN WITH NUMBERS. Show all posts
FIND SQUARE OF NUMBERS IN 200 TO 299
Posted by
SHRENIK
on Wednesday, September 16, 2009
Labels:
FUN WITH NUMBERS,
SQUARE OF A NUMBER
/
Comments: (2)
QUIZ
Posted by
SHRENIK
on Friday, July 24, 2009
Labels:
FUN,
FUN WITH NUMBERS
/
Comments: (9)
can anyone make 3 using two 2's???
ONE ANSWER IS
2^0 + 2=3
IF YOU HAVE ANY ANSWER POST IT AS COMMENT........
ONE ANSWER IS
2^0 + 2=3
IF YOU HAVE ANY ANSWER POST IT AS COMMENT........
EASY MULTIPLICATION TRICK
Posted by
SHRENIK
Labels:
FUN WITH NUMBERS,
multiply
/
Comments: (1)
Method for multiplying numbers where the first figures are the same and the last figures add up to 10
FOR EG:
32 x 38 = 1216
Both numbers here start with 3 THEY ARE SAME and the last
figures (2 and 8) add up to 10
So we just multiply 3 by 4 (the next number up)
to get 12 for the first part of the answer.
And we multiply the last figures: 2 x 8 = 16 to
get the last part of the answer.
· And 81 x 89 = 7209
We put 09 since we need two figures as in all the other examples
FOR EG:
32 x 38 = 1216
Both numbers here start with 3 THEY ARE SAME and the last
figures (2 and 8) add up to 10
So we just multiply 3 by 4 (the next number up)
to get 12 for the first part of the answer.
And we multiply the last figures: 2 x 8 = 16 to
get the last part of the answer.
· And 81 x 89 = 7209
We put 09 since we need two figures as in all the other examples
MATHS PUZZLE
Posted by
SHRENIK
Labels:
FUN,
FUN WITH NUMBERS,
MATHS,
PUZZLE
/
Comments: (7)
solve this
Village A has a population of 70,000, which is decreasing at the rate of 1000 per year.
Village B has a population of 52000, which is increasing at the rate of 400 half yearly
.How many years will they take to reach same population
try its easy .............
leave your answer as a comment......
ANSWER
let,after x yrs their will b same...
after x yrs in A population decreases 1000x & in B population increases (2*400*x)=800x .
So,
70000-1000x = 52000 + 800x
x= 10
Village A has a population of 70,000, which is decreasing at the rate of 1000 per year.
Village B has a population of 52000, which is increasing at the rate of 400 half yearly
.How many years will they take to reach same population
try its easy .............
leave your answer as a comment......
ANSWER
let,after x yrs their will b same...
after x yrs in A population decreases 1000x & in B population increases (2*400*x)=800x .
So,
70000-1000x = 52000 + 800x
x= 10
SIMPLE TRICKS TO MULTIPLY
Posted by
SHRENIK
on Wednesday, July 15, 2009
Labels:
FUN,
FUN WITH NUMBERS,
MAGIC,
multiply
/
Comments: (1)
Multiply by 5: Multiply by 10 and divide by 2.
Multiply by 6: Sometimes multiplying by 3 and then 2 is easy.
Multiply by 9: Multiply by 10 and subtract the original number.
Multiply by 12: Multiply by 10 and add twice the original number.
Multiply by 13: Multiply by 3 and add 10 times original number.
Multiply by 14: Multiply by 7 and then multiply by 2
Multiply by 15: Multiply by 10 and add 5 times the original number, as above.
Multiply by 16: You can double four times, if you want to. Or you can multiply by 8 and then by 2.
Multiply by 17: Multiply by 7 and add 10 times original number.
Multiply by 18: Multiply by 20 and subtract twice the original number (which is obvious from the first step).
Multiply by 19: Multiply by 20 and subtract the original number.
Multiply by 24: Multiply by 8 and then multiply by 3.
Multiply by 27: Multiply by 30 and subtract 3 times the original number (which is obvious from the first step).
Multiply by 45: Multiply by 50 and subtract 5 times the original number (which is obvious from the first step).
Multiply by 90: Multiply by 9 (as above) and put a zero on the right.
Multiply by 98: Multiply by 100 and subtract twice the original number.
Multiply by 99: Multiply by 100 and subtract the original number.
Multiply by 6: Sometimes multiplying by 3 and then 2 is easy.
Multiply by 9: Multiply by 10 and subtract the original number.
Multiply by 12: Multiply by 10 and add twice the original number.
Multiply by 13: Multiply by 3 and add 10 times original number.
Multiply by 14: Multiply by 7 and then multiply by 2
Multiply by 15: Multiply by 10 and add 5 times the original number, as above.
Multiply by 16: You can double four times, if you want to. Or you can multiply by 8 and then by 2.
Multiply by 17: Multiply by 7 and add 10 times original number.
Multiply by 18: Multiply by 20 and subtract twice the original number (which is obvious from the first step).
Multiply by 19: Multiply by 20 and subtract the original number.
Multiply by 24: Multiply by 8 and then multiply by 3.
Multiply by 27: Multiply by 30 and subtract 3 times the original number (which is obvious from the first step).
Multiply by 45: Multiply by 50 and subtract 5 times the original number (which is obvious from the first step).
Multiply by 90: Multiply by 9 (as above) and put a zero on the right.
Multiply by 98: Multiply by 100 and subtract twice the original number.
Multiply by 99: Multiply by 100 and subtract the original number.
Square 2 Digit Number:WITH UP-DOWN Method
Posted by
SHRENIK
Labels:
FUN,
FUN WITH NUMBERS,
SQUARE OF A NUMBER
/
Comments: (1)
Square a 2 Digit Number, for this example 37:
> Look for the nearest 10 boundary
> In this case up 3 from 37 to 40.
> Since you went UP 3 to 40 go DOWN 3 from 37 to 34.
> Now mentally multiply 34x40
> The way I do it is 34x10=340;
> Double it mentally to 680
> Double it again mentally to 1360
> This 1360 is the FIRST interim answer.
> 37 is "3" away from the 10 boundary 40.
> Square this "3" distance from 10 boundary.
> 3x3=9 which is the SECOND interim answer.
> Add the two interim answers to get the final answer.
> Answer: 1360 + 9 = 1369
> Look for the nearest 10 boundary
> In this case up 3 from 37 to 40.
> Since you went UP 3 to 40 go DOWN 3 from 37 to 34.
> Now mentally multiply 34x40
> The way I do it is 34x10=340;
> Double it mentally to 680
> Double it again mentally to 1360
> This 1360 is the FIRST interim answer.
> 37 is "3" away from the 10 boundary 40.
> Square this "3" distance from 10 boundary.
> 3x3=9 which is the SECOND interim answer.
> Add the two interim answers to get the final answer.
> Answer: 1360 + 9 = 1369
TRICK TO SUBSTRACT NUMBER EASILY
Posted by
SHRENIK
Labels:
FUN,
FUN WITH NUMBERS,
SUBSTRACT
/
Comments: (1)
this is an easy trick
To subtract a large number from 1,000
subtract all but the last number from 9, then subtract the last number from 10
1000
-547
step1: subtract 5 from 9 = 4
step2: subtract 4 from 9 = 5
step3: subtract 7 from 10 = 3
answer: 453
To subtract a large number from 1,000
subtract all but the last number from 9, then subtract the last number from 10
1000
-547
step1: subtract 5 from 9 = 4
step2: subtract 4 from 9 = 5
step3: subtract 7 from 10 = 3
answer: 453
BEAUTY OF MATHS
Posted by
SHRENIK
on Saturday, June 27, 2009
Labels:
FUN,
FUN WITH NUMBERS
/
Comments: (1)
1 x 8 + 1 = 9
12 x 8 + 2 = 98
123 x 8 + 3 = 987
1234 x 8 + 4 = 9876
12345 x 8 + 5 = 98765
123456 x 8 + 6 = 987654
1234567 x 8 + 7 = 9876543
12345678 x 8 + 8 = 98765432
123456789 x 8 + 9 = 987654321
1 x 9 + 2 = 11
12 x 9 + 3 = 111
123 x 9 + 4 = 1111
1234 x 9 + 5 = 11111
12345 x 9 + 6 = 111111
123456 x 9 + 7 = 1111111
1234567 x 9 + 8 = 11111111
12345678 x 9 + 9 = 111111111
123456789 x 9 + 10 = 1111111111
9 x 9 + 7 = 88
98 x 9 + 6 = 888
987 x 9 + 5 = 8888
9876 x 9 + 4 = 88888
98765 x 9 + 3 = 888888
987654 x 9 + 2 = 8888888
9876543 x 9 + 1 = 88888888
98765432 x 9 + 0 = 888888888
1 x 1 = 1
11 x 11 = 121
111 x 111 = 12321
1111 x 1111 = 1234321
11111 x 11111 = 123454321
111111 x 111111 = 12345654321
1111111 x 1111111 = 1234567654321
11111111 x 11111111 = 123456787654321
111111111 x 111111111 = 12345678987654321
12345679 x 9 = 111111111
12345679 x 18 = 222222222
12345679 x 27 = 333333333
12345679 x 36 = 444444444
12345679 x 45 = 555555555
12345679 x 54 = 666666666
12345679 x 63 = 777777777
12345679 x 72 = 888888888
12345679 x 81 = 999999999
9 x 9 = 81
99 x 99 = 9801
999 x 999 = 998001
9999 x 9999 = 99980001
99999 x 99999 = 9999800001
999999 x 999999 = 999998000001
9999999 x 9999999 = 99999980000001
99999999 x 99999999 = 9999999800000001
999999999 x 999999999 = 999999998000000001
6 x 7 = 42
66 x 67 = 4422
666 x 667 = 444222
6666 x 6667 = 44442222
66666 x 66667 = 4444422222
666666 x 666667 = 444444222222
6666666 x 6666667 = 44444442222222
66666666 x 66666667 = 4444444422222222
666666666 x 666666667 = 444444444222222222
12 x 8 + 2 = 98
123 x 8 + 3 = 987
1234 x 8 + 4 = 9876
12345 x 8 + 5 = 98765
123456 x 8 + 6 = 987654
1234567 x 8 + 7 = 9876543
12345678 x 8 + 8 = 98765432
123456789 x 8 + 9 = 987654321
1 x 9 + 2 = 11
12 x 9 + 3 = 111
123 x 9 + 4 = 1111
1234 x 9 + 5 = 11111
12345 x 9 + 6 = 111111
123456 x 9 + 7 = 1111111
1234567 x 9 + 8 = 11111111
12345678 x 9 + 9 = 111111111
123456789 x 9 + 10 = 1111111111
9 x 9 + 7 = 88
98 x 9 + 6 = 888
987 x 9 + 5 = 8888
9876 x 9 + 4 = 88888
98765 x 9 + 3 = 888888
987654 x 9 + 2 = 8888888
9876543 x 9 + 1 = 88888888
98765432 x 9 + 0 = 888888888
1 x 1 = 1
11 x 11 = 121
111 x 111 = 12321
1111 x 1111 = 1234321
11111 x 11111 = 123454321
111111 x 111111 = 12345654321
1111111 x 1111111 = 1234567654321
11111111 x 11111111 = 123456787654321
111111111 x 111111111 = 12345678987654321
12345679 x 9 = 111111111
12345679 x 18 = 222222222
12345679 x 27 = 333333333
12345679 x 36 = 444444444
12345679 x 45 = 555555555
12345679 x 54 = 666666666
12345679 x 63 = 777777777
12345679 x 72 = 888888888
12345679 x 81 = 999999999
9 x 9 = 81
99 x 99 = 9801
999 x 999 = 998001
9999 x 9999 = 99980001
99999 x 99999 = 9999800001
999999 x 999999 = 999998000001
9999999 x 9999999 = 99999980000001
99999999 x 99999999 = 9999999800000001
999999999 x 999999999 = 999999998000000001
6 x 7 = 42
66 x 67 = 4422
666 x 667 = 444222
6666 x 6667 = 44442222
66666 x 66667 = 4444422222
666666 x 666667 = 444444222222
6666666 x 6666667 = 44444442222222
66666666 x 66666667 = 4444444422222222
666666666 x 666666667 = 444444444222222222
Temperature Conversion
Posted by
SHRENIK
Labels:
FUN,
FUN WITH NUMBERS,
MATHS,
TEMPERATURE CONVERSION
/
Comments: (2)
Temperature Conversion
This is a easy trick to convert Fahrenheit to Celsius & vice versa.
The answer you will get will not be an exact one, but it will give you an idea of the temperature you are looking at.
Fahrenheit to Celsius:
Take 30 away from the Fahrenheit, then divide the answer by 2. This is your answer in Celsius.
Example:
94 Fahrenheit - 30 = 64. Then divide by two, 32 Celsius.
so 94 Fahrenheit = 32 Celsius.
Celsius to Fahrenheit just do the reverse:
Double it, then add 30.
40 Celsius double it, is 80, then add 30 is 110
40 Celsius = 110 Fahrenheit
This is a easy trick to convert Fahrenheit to Celsius & vice versa.
The answer you will get will not be an exact one, but it will give you an idea of the temperature you are looking at.
Fahrenheit to Celsius:
Take 30 away from the Fahrenheit, then divide the answer by 2. This is your answer in Celsius.
Example:
94 Fahrenheit - 30 = 64. Then divide by two, 32 Celsius.
so 94 Fahrenheit = 32 Celsius.
Celsius to Fahrenheit just do the reverse:
Double it, then add 30.
40 Celsius double it, is 80, then add 30 is 110
40 Celsius = 110 Fahrenheit
TRICK TO GET UR TELEPHONE NUMBER
Posted by
SHRENIK
on Wednesday, March 25, 2009
Labels:
CALCULATOR TRICK,
FUN,
FUN WITH NUMBERS,
MAGIC
/
Comments: (3)
1. take a calculator
2. Key in the first 4 digits of your phone number (eg if ur landline is 2888xxxx TAKE 2888)
3. Multiply by 80
4. Add 1
5. Multiply by 250
6. Add the last 4 digits of your phone number
7. Add the last 4 digits of your phone number again
8. Subtract 250
9. Divide number by 2
Do you recognize the answer
yes its ur landline number................
2. Key in the first 4 digits of your phone number (eg if ur landline is 2888xxxx TAKE 2888)
3. Multiply by 80
4. Add 1
5. Multiply by 250
6. Add the last 4 digits of your phone number
7. Add the last 4 digits of your phone number again
8. Subtract 250
9. Divide number by 2
Do you recognize the answer
yes its ur landline number................
FUNNY CALCULATOR TRICK
Posted by
SHRENIK
Labels:
CALCULATOR TRICK,
FUN,
FUN WITH NUMBERS,
MATHS
/
Comments: (0)
1. take a calculator
2. type in "12345679" (remember not 8)
3. times it by any number multiplied by 9,
lets say if u you want 5as answer , 5*9=45, so 12345679*45=?
try multiplying by: 9,18,27,36 and so on...
& see the magic of maths
2. type in "12345679" (remember not 8)
3. times it by any number multiplied by 9,
lets say if u you want 5as answer , 5*9=45, so 12345679*45=?
try multiplying by: 9,18,27,36 and so on...
& see the magic of maths