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Retro Review: Radio Shack EC-2024

Retro Review:  Radio Shack EC-2024

Quick Facts

Company:  Radio Shack
Years in Production: Around 1994
Original Price: $24.99
Battery:  Solar with Battery backup  (RS 389A)
Type:  Desktop- Fold-able
Number of Digits: 10

Initial cost and year came from the CALCUSUEM web site:  (retrieved August 4, 2019)

I paid $3 for this at a swap meet. 


The some of the keys are larger than the others.  The plus key has an L-shape, while the minus key is large, and the equals key, labeled the “ANSWER BAR”.

The keyboard is alright.  If you type at a reasonable pace, the keys are responsive.  If you are speed typist, prepare to be disappointed. 

The EC-2024 works best when the calculator is under full light. 


There are two settings switches:

Rounding:  always round up, always round down, or 5/4 (use the general rounding rules)

Decimal Setting:  float, 0 decimal places, 2 decimal places, 3 decimal places, or add mode.  In add mode, every number that is added or subtracted is automatically divided by 100.  This allows for rapid entry of dollars and cents without having to enter the decimal point. 

The Δ% Key

How the percent key [ Δ% ] depends on what arithmetic operation is used with it.

x [ + ] y [ Δ%] returns (x + y)/y * 100%

Example:  250 [ + ] 300 [ Δ% ] returns 183.3333333

x [ – ] y [ Δ% ] returns (x – y)/y * 100%

Example:  250 [ – ] 300 [ Δ% ] returns -16.66666666

(This is the true percent change function, x is new, y is old)

x [ * ] y [ Δ% ] returns x + x * y / 100

Example:  250 [ * ] 300 [ Δ% ] returns 1000

x [ ÷ ] y [ Δ% ] returns x/(1 – y/100)

Example:  250 [ ÷ ] 300 [ Δ% ] returns -125


It’s a nice calculator and will fulfill the basic needs.  The keyboard is nice and fold-able.  If you get it, spending a few dollars (like no more than $5) is good. 


All original content copyright, © 2011-2019.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.