How to Use a Calculator for Converting Fractions and Decimals
To convert between fractions and decimals on a scientific calculator you use the
blue F
D (fraction and decimal conversion) button above the PRB button as shown below.
Converting fractions and mixed numbers to decimals:
Even though we could use the fraction and decimal conversion button, it’s easier to simply
divide the numerator by the denominator.
To convert 5/8 to a decimal, you type in 5 ÷ 8 =
You should get 0.625
To convert 123/12 to a decimal, write down the whole number followed by a decimal point, then
type in 3 ÷ 12 to get the decimal part of the number. You should get 12.25 (3 ÷ 12 = 0.25).
Converting decimals to fractions and mixed numbers:
To convert a decimal to a fraction (automatically in lowest terms…yay!), simply type in the
decimal, press the blue 2nd button (this gives you access to the blue functions above the black
keys), the PRB button (since the fraction/decimal converter button is above it) then =
Convert 0.528 to a fraction. Type in .528 blue 2nd button, PRB, then =
You should get 66/125.
To convert -8.24 to a mixed number, (-)8.24, blue 2nd button, PRB =
(You can also just type in the .24 as long as you remember to put the -8 in front of the fraction
once converted.)
You should get -86/25.
Practice: (Answers at the end of the document)
Perform each operation below (review tutorial on fraction operations, if necessary). Write your
answers as both a fraction/mixed number and a decimal.
1) 46/11 - 23/4 =
2) 5.5 ÷ 2.95 + 1/4 =
3) 17.45 + 9 x 3.2 =
Answers: 1) 135/44 or 1.7954 2) 227/236 or 2.1144.678 3) 461/4 or 46.25