### 9.1.2 Computing with units

Xcas performs usual arithmetic operations (+, -, *, /, `^`) on unit objects. Different units may be used, but they must be compatible for + and -. The result is an unit object

- for the multiplication and the division of two unit objects _u1 and _u2 the unit of the result is written _(u1*u2) or _(u1/u2).
- for an addition or a subtraction of compatible unit objects, the result is expressed with the same unit as the first term of the operation.

Input :

1_m+100_cm

Output :

2_m

Input :

100_cm+1_m

Output :

200_cm

Input :

1_m*100_cm

Output :

1_m`^`2