What is 4.2 as a fraction?

The number 4.2 can be written as a fraction as follows:

To convert a decimal to a fraction, we need to identify the place value of the decimal. In this case, the 2 is in the tenths place.

Since there are 10 tenths in a whole, we can write 4.2 as 42 tenths.

Now, we can express it as a fraction: 4.2 = 42/10

However, fractions are usually simplified, so we can divide both the numerator and denominator by their greatest common divisor, which in this case is 2.

42/10 = (42 ÷ 2) / (10 ÷ 2) = 21/5

Therefore, 4.2 can be written as the fraction 21/5.