14,200,000 convert to scientific ?

1.42 x 10^7

To convert to scientific notation, always put the decimal after the first non-zero digit. In your case, after the 1 and before the 42. Drop any leading or trailing zeroes.

That gets you:
1.42

But then you need to figure out what power of 10 to put after it.

Compare the decimal places on the new number and the old number:
1.42
14200000.

Notice how you have to move the decimal place 7 spaces to the right to get to the old number. That means you should multiply the number by 10^7. This is equivalent multiplying by 10 million (10,000,000) which, as you notice, has seven zeroes. That's another way to remember it.

The final answer is:
1.42 x 10^7

1.42 x 10^7

1.42 x 10^7

1.42 x 10⁷

1.42 x 10^7

14200000
= 1.42 x 10000000
= 1.42 x 10^7

1,42* 10^7

1.42 * 10^7

1.42 x 10^7