Divisible by 7 (Math Trick)...

A number is divisible by 7 if, subtract 2 times the last digit from the remaining number and its result is divisible by 7.

Let us we will apply this interesting math rule on following examples.

Is 203 divisible by 7?

Here the last number is 3 and remaining is 20. Apply the above rule. i.e. Double the last digit (3) and subtract it from remaining number (20)

Now the result 14 is divisible by 7 so 203 is divisible by 7.
(Do this step in your mind)

Is 3164 divisible by 7?

Here 308 is big number (If you feel difficult to divide you can apply the rule again).

Now the result 14 is divisible by 7 so the number 3164 is also divisible by 7.
(Do this step in your mind)

Is 108346 divisible by 7?

Now the result 91 is divisible by 7, so the number 108346 is also divisible by 7.
(Do this step in your mind)

SHORTCUT TRICKS (Division)

Divisible by 2 Shortcut trick

Divisible by 3 Shortcut trick

Divisible by 4 Shortcut trick

Divisible by 5 Shortcut trick

Divisible by 6 Shortcut trick

Divisible by 7 Shortcut trick

Divisible by 8 Shortcut trick

Divisible by 9 Shortcut trick

Divisible by 10 Shortcut trick

SHORTCUT TRICKS (Prime Number)

Find the prime number from 1 to 100 just in 5 second (MATH PRIME NUMBER SHORTCUT TRICK from 1 to 100 number) ?

Find a large number "A" is prime number or not (MATH PRIME NUMBER SHORTCUT TRICK By using Square Root method) ?

Find the composite number from 1 to 100 just in 5 second (MATH COMPOSITE NUMBER SHORTCUT TRICK from 1 to 100 number) ?

Worksheets (Solved)

Matrix Logarithm

Trigonometric Identities

Application of Trigonometry

Integration