Multiply both the numerator and denominator by 10 for each digit after the decimal point.
In order to reduce the fraction find the Greatest Common Factor (GCF) for 4 and 10. Keep in mind a factor is just a number that divides into another number without any remainder.
Now to reduce the fraction we divide both the numerator and denominator by the GCF value.
Scroll down to customize the precision point enabling 0.4 to be broken down to a specific number of digits.
The page also includes a pie chart representation of 0.4 in fraction form, the different types of fractions, and what type of fraction 0.4 is when converted.
The level of precision are the number of digits to round to. Select a lower precision point below to break decimal 0.4 down further in fraction form. The default precision point is 5. If the last trailing digit is "5" you can use the "round half up" and "round half down" options to round that digit up or down when you change the precision point.
For example 0.875 with a precision point of 2 rounded half up = 88/100, rounded half down = 87/100.
0.4 = 0 4/10
numerator/denominator = 4/10
A mixed number is made up of a whole number (whole numbers have no fractional or decimal part) and a proper fraction part (a fraction where the numerator (the top number) is less than the denominator (the bottom number). In this case the whole number value is empty and the proper fraction value is 4/10.
Not all decimals can be converted into a fraction. There are 3 basic types which include:
Terminating decimals have a limited number of digits after the decimal point.
Example: 5310.2978 = 5310 2978/10000
Recurring decimals have one or more repeating numbers after the decimal point which continue on infinitely.
Example: 3483.3333 = 3483 3333/10000 = 333/1000 = 33/100 = 1/3 (rounded)
Irrational decimals go on forever and never form a repeating pattern. This type of decimal cannot be expressed as a fraction.
You can also see the reverse conversion I.e. how fraction 4/10 is converted into a decimal.
Click any decimal to see it as a fraction:
Click any decimal to see the converted fraction value:
Click a decimal to convert into a fraction: