I assume you mean a decimal number. Move the point to the right, counting the steps until at last you have no more numbers to the right, or only zeros. Each step is equivalent to multiplying by 10. Suppose there are N steps. The number you now have on the left, divided by 1 followed by N zeros is your fraction. So 1.234 becomes (with 3 steps) 1234/1000
Convert the mixed fraction to an improper fraction, multiply by the whole number, convert the answer back to a mixed fraction (if required).
Since 126126 is a whole number, there is no need to convert it into a fraction.
To convert a fraction to a decimal divide the numerator (top number) by the denominator (bottom number). To convert a decimal (or fraction) to a percentage multiply it by 100 %.
You can convert any whole number to a fraction by putting it over one.
Convert the mixed number to an improper fraction and proceed with the multiplication.
Convert the mixed number to an improper fraction. Convert the whole number to a fraction with a common denominator. Proceed with the subtraction.
convert it into a mixed number
You do not do anything. An improper fraction IS a real number.
Convert the mixed number to an improper fraction and proceed.
Convert the mixed number to a fraction and invert numerator and denominator
You take the bottom number and divided by the top number.
You can't. Improper and proper fractions are two different things. You can convert an improper fraction to a mixed number.