Easily Multiply any Number with 11

Want to know how to calculate multiples of 11 at your fingertips ?

Lets take an Example ,

1. If you want 235 x 11 = ?
2. Write the left most number first                                                     2
3. Now add first digit with second and write it after first one           25
4. Repeat the procedure.        (3+5=8)                                               258
5. At last write the Leftmost number                                                 2585

So 235 x 11 = 2585

Wasn't That too Simple ???

Divisibility Rules

The Divisibility Rules

These rules let you test if one number is divisible by another, without having to do too much calculation!

Divisible by:	If:	Examples:
2	The last digit is even (0,2,4,6,8)	128 is 129 is not
3	The sum of the digits is divisible by 3	381 (3+8+1=12, and 12÷3 = 4) Yes 217 (2+1+7=10, and 10÷3 = 3 1/3)No
4	The last 2 digits are divisible by 4	1312 is (12÷4=3) 7019 is not
5	The last digit is 0 or 5	175 is 809 is not
6	The number is divisible by both 2 and 3	114 (it is even, and 1+1+4=6 and 6÷3 = 2) Yes 308 (it is even, but 3+0+8=11 and 11÷3 = 3 2/3) No
7	If you double the last digit and subtract it from the rest of the number and the answer is: 0, or divisible by 7 (Note: you can apply this rule to that answer again if you want)	672 (Double 2 is 4, 67-4=63, and 63÷7=9) Yes 905 (Double 5 is 10, 90-10=80, and 80÷7=11 3/7) No
8	The last three digits are divisible by 8	109816 (816÷8=102) Yes 216302 (302÷8=37 3/4) No
9	The sum of the digits is divisible by 9 (Note: you can apply this rule to that answer again if you want)	1629 (1+6+2+9=18, and again, 1+8=9) Yes 2013 (2+0+1+3=6) No
10	The number ends in 0	220 is 221 is not
11	If you sum every second digit and then subtract all other digits and the answer is: 0, or divisible by 11	1364 ((3+4) - (1+6) = 0) Yes 3729 ((7+9) - (3+2) = 11) Yes 25176 ((5+7) - (2+1+6) = 3) No
12	The number is divisible by both 3 and 4	648 (By 3? 6+4+8=18 and 18÷3=6 Yes. By 4? 48÷4=12 Yes) Yes 524 (By 3? 5+2+4=11, 11÷3= 3 2/3 No. Don't need to check by 4.) No

There are lots more! Not only are there divisibility tests for larger numbers, but there are more tests for the numbers we have shown.

In the Next Post I will tell you how to check divisibility by ANY NUMBER.
The link to Next Post is This.

Actually this is the method to generate Divisibility Rules For Any Number.