EC-235 8-Digit Pocket Calculator
OWNER’S MANUAL — Please read before using this equipment.
Your RadioShack
Percentage Key — simplifies discount, percentage, and tax calcula- tions.
Square Root Key — quickly computes the square root of the dis- played number.
Constant Calculations — let you add, subtract, divide, or multiply the same number over and over without having to
Large
lation results.
Protective Wallet — protects the calculator’s keypad.
OPERATION
You can enter basic, mixed, percentage,
Press ON/C to turn on your calculator.
If you do not press a key for about 8 minutes, your calculator automatically turns off. To turn it off sooner, press OFF.
Correcting Entry Errors
If you enter an incorrect value, press CE (Clear Entry) once. Then enter the correct value and continue your calculation.
To clear the display for a new calculation,
press ON/C (On/Clear) so 31 appears (this also clears the calculator’s memory). Then begin the new calculation.
If you press an incorrect operator key (+,
Exponential, Square Root,
and Reciprocal Calculations
Calculation | You Press | You See | ||
|
|
|
|
|
|
|
|
|
|
23 = 8 | 2 ⋅ = = | ;1 | ||
The square root of 2 is 1.4142135 | 2 |
|
| 417475468 |
|
| |||
|
|
|
|
|
1/8 = 0.125 | 8 ⎟ = | 31458 | ||
Memory Calculations
To store a value in memory, first clear the memory and the display by pressing MRC (Memory Recall/Clear) twice, then press CE.
To add a value to memory, enter the number or calculation you want to add, then press M+. The calculator totals the current calculation (if one is pending) and adds that value to memory.
To subtract a value from memory, enter the number or calculation you want to subtract, then press
To recall the value from memory, press MRC once.
Calculation Errors
(5525 appears when:
•A calculation result exceeds 8 digits. This is an overflow error (see “Estimating Calculation Results” ).
•A memory calculation result exceeds 8 digits to the left of the dec- imal point. The memory contents remain unchanged.
•You try to divide by 0.
•You try to calculate the square root of a negative number.
If (5525 appears, press ON/C to clear the error.
Constant Calculations
For addition, subtraction, and division, the value you enter before pressing = is the constant. For multiplication, the value you enter be- fore pressing ⋅ is the constant.
Calculation | You Press | You See |
|
|
|
|
|
|
7 + 3 = 10 | 7 + 3 = | 431 |
5 + 3 = 8 | 5 = | ;1 |
|
|
|
260 ⋅ 12.3 = 3198 | 260 ⋅ 12.3 = | 64<;1 |
260 ⋅ 4.15 = | 4.15 = | 43:<1 |
|
|
|
Estimating Calculation Results
If you perform an operation that results in an overflow error, you can estimate the correct result (to 8 significant digits) by following these steps.
1.Count the number of digits to the left of the decimal point.
2.Remove the decimal point.
3.Add as many zeros to the right of the number as there were digits to the left of the decimal point.
For example, if (5525# 413475397 appears, the approximate answer is 101,420,640. If (5525# 64<1:367: appears, the approximate answer is
31,970,347,000.
© 2000 RadioShack Corporation.
All Rights Reserved.
RadioShack and RadioShack.com are trademarks used by RadioShack Corporation.
