That is simply called a constant.
A variable in an experiment that stays the same is a constant.
The constant variable.
control variable or constant
Gravity is a constant not a variable. (stays constant at 9.8ms/s in earths atmosphere)
constant
constant
Control
A variable in an experiment that stays the same is a constant.
variable that stays the same, it does not change at all....
constant variable
The constant variable is usually the 'X' variable or the variable that stays the same. For example, it may be the 'X' variable or the same number.
The constant is the value that stays the same throughout your experiment, whereas the variable value changes.