To find the number of centimeters in 10 inches, multiply the number of inches given (10) by 3.04 2.54 2.78 2.44

We have that 1 in 2.54 cm
                      10 inX
x=10*2.54=25.4 cms

the answer is 2.54 cms

What you must do for this case is to know the conversion of inches to centimeters:
 1 inch = 2.54 centimeters
 We can make the following rule of three:
 1 ---> 2.54
 10 > x
 Clearing x:
 x = (10/1) * (2.54)
 x = 25.4 cm
  
 multiply the number of inches given by 
 2.54