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### Find the composite number from 1 to 100 just in 5 second (Math Composite Number Shortcut tricks)...

An interesting math shortcut composite number trick find the composite number from 1 to 100 (Just in 5 second) Before starting this math shortcuts composite number trick let us revise the composite number defination.

```Composite Number
```

"A number that can be divided exactly by numbers other than 1 or itself is called a composite number" i.e 4, 6, 8, 9, 10... notice that 1 is not included in composite number and 2, 3 are in prime number list therefore composite number are starting from 4.

This math shortcuts composite number trick is used to find all composite numbers between 1 and 100.
First arrange numbers in a table like following chart. Enter 6 numbers in each row then start the next row. 1- Cross out 1 because according to defination it is not composite

2- Cross out 2 with a Red color then draw red line (for cross out) on all multiple of 2. 3- Cross out 3 with a blue color then draw blue line (for composite) on all multiple of 3.

4- Cross out 5 with a Green color then draw Green line (for composite) on all multiple of 5.

5- Cross out 7 with a Yellow color then draw Yellow line (for composite) on all multiple of 7. 6- Cross out 11 and search for multiple of 11 in remaining number. We notice that there is no multiple of 11 in remaining numbers. Cross out the remaining number where no line was drawn.

7- No need further process because there is no multiple exist in remaining numbers. Non crossed number where coloured line was drown are composite number. Thefore the composite number between 1 and 100 are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.
They are total 25.

##### 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

##### Worksheets (Solved)

###### Integration     