# Question about float / double / decimal

Hey there. Just started learning programming on codeacademy, decided to start with C#. In the course, i have to use writeline to print the weight of a dog, a fractional number , “65.22”, it should be small enough for it to be included in the float library and decimal should be big enough to include it as well, right? but i get an error using any of them, and i can only use double, anybody knows why that is?

Hello @py9357380041, welcome to the forums! Can you post your code with a screenshot of the error, please?

Sure !

same error if i use decimal, only works using double

I think this occurs because the default decimal number on C# is `double` (meaning to create floats or decimals, you have to do things with the number, such as add an `f` to the beginning of it), it wants to convert the number `65.22` to a `float`, but since that’s a lossy conversion (meaning data could be lost, as floats hold less information than doubles), you have to actually tell the code you want it converted.

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The Decimal, Double, and Float variable types are different in the way that they store the values. The main difference is Float and Double are binary floating point types and a Decimal will store the value as a floating decimal point type. So Decimals have much higher precision and are usually used within monetary (financial) applications that require a high degree of accuracy. But in performance wise Decimals are slower than double and float types. Precision is the main difference where float is a single precision (32 bit) floating point data type, double is a double precision (64 bit) floating point data type and decimal is a 128-bit floating point data type.

• Float - 7 digits (32 bit)
• Double-15-16 digits (64 bit)
• Decimal -28-29 significant digits (128 bit)

Decimals have much higher precision and are usually used within financial applications that require a high degree of accuracy. Decimals are much slower (up to 20X times in some tests) than a double/float. Decimals and Floats/Doubles cannot be compared without a cast whereas Floats and Doubles can. Decimals also allow the encoding or trailing zeros.