CALC 1 has the following ways to store/ recall numbers:

- Storing a number you will want to use or view later using the STO and RCL keys.
- Recalling values automatically stored in the History list.
- Storing, recalling and calculating values used in Function Calculators and some Focused Calculators using auto STO.
- Recalling values automatically stored in the an automatic stack.

The

key copies the value from the x register into a storage variable. Storage variables a-w are general purpose user variables. If there was a pending expression, pressing STO then "u", for example, will evaluate the expression before storing it in the "u" variable.

The

key copies the value from the storage variable into the x register.

If you are entering a expression in chain mode, 5 + RCL b, the expression will be "5.00 + 12.00" for the value of 12.00 in b.

If you are entering a expression in algebraic mode, 5 + RCL b, the expression will be "5 + b".

So if you have a pending expression in ALG calculation mode, RCL will insert the variable into the expression. Otherwise the value will be placed in the x register.

If you need to begin the expression with a variable in ALG mode, tap the "←" then RCL b + 5 to get "b + 5" as the expression.

With Key Preview, tapping STO or RCL will display the value of the respective storage variable on the key. This feature makes it easy to see which variables are available and the values of used variables.

STO + key a - w | Adds x to the selected memory location. |

STO - key a - w | Subtracts x from the selected memory location. |

STO × key a - w | Multiplies the selected memory location by x. |

STO ÷ key a - w | Divides the selected memory location by x. |

RCL + key a - w | Adds the selected memory location to x. |

RCL - key a - w | Subtracts the selected memory location from x. |

RCL × key a - w | Multiplies x by the selected memory location. |

RCL ÷ key a - w | Divides x by the selected memory location. |

The last 200 results of every expression and key calculation is stored in the History list. The history list shows you the results along with the expression or key used to calculate it. Tapping the row will enter the value into the x register.

For many functions the value used will be stored in the 'last x' register. Tap 'RCL, last x' (located on the bottom row) to recall this value.

The expression Calculators will automatically assume that if you enter a number or expression and tap one of the expression parameter keys that you wish to store the value. So after keying in "150", there is no need to tap =, then STO, then the "old" value key in the Percent Change calculator. Just tap "150" then "old". The "AS" indicator will appear in the display when Auto STO is active. See the Auto STO page. "Long press" the key and the hint will tell you if a Store or Calculation will take place.

The Automatic Stack keeps the last 4 results. Tapping SWAP and ROLL will bring the values to the x() register.

RPN users are familiar with the automatic stack. With CALC 1, users who prefer the chain calculation mode will also find the automatic stack useful in incorporating recent results in calculations. See the Calculations Using the Chain (CHN) Calculation Mode for an example.

Some calculators (TVM, Triangles, ...) have keys to store multiple values associated with the Focused Calculator.