**Summation**

Press **MENU 9** to access the CAS menu, press
**2** to access the CALC menu, then press **4** to select **4:****S**.
One can then evaluate summations. Apply the syntax

(summand, index of summation, lower index of summation, upper index of summation).

For example, to evaluate , after S( is pasted in the entry line, enter

**X X ^{2} , X , 1 , 1 0 ) EXE**

One
may also use the alpha key to enter the index as i or k as used more often in
summation notation. For example, to compute the sum of *k*^{2} as
*k* goes from 1 to 10, first select **4:** from the CALC menu. Then,
after ( is pasted in the entry line, enter

**ALPHA K ^ 2 , ALPHA
K , 1 , 1 0 ) EXE**

To evaluate , after ( is pasted in the entry line, enter

**ALPHA K ^ 2 , ALPHA K
, 1 , ALPHA N ) EXE**

The Casio can evaluate some basic infinite series, such as a geometric series; for example, . After ( is pasted in the entry line, enter

**. 3 ^ X , X , 1 , OPTN F1 ) EXE**