EC240 - Calculator AURORA - Free user manual and instructions

Product Type	Basic Desktop Calculator
Brand	Aurora
Model	EC240
Display	8-digit LCD
Power Source	Solar cell with LR54 battery backup
Dimensions (L x W x H)	100 x 60 x 10 mm
Weight	45 g
Basic Arithmetic	Addition, subtraction, multiplication, division
Additional Functions	Percentage, square root, memory (M+, M-, MR, MC)
Auto Power-Off	Approximately 7 minutes of inactivity
Keyboard	Plastic keys with tactile feedback
Case Material	ABS plastic
Operating Temperature	0°C to 40°C
Cleaning	Wipe with a dry soft cloth; avoid solvents
Safety	Keep away from water and excessive heat
Spare Parts / Repairability	Battery replacement (LR54); no user-serviceable parts inside
General Information	Designed for everyday calculations at home or office

Frequently Asked Questions - EC240 AURORA

How do I replace the battery?

Slide off the back cover, remove the old LR54 battery, insert a new one with the correct polarity, and replace the cover. The solar cell will power the calculator in good light, but battery backup ensures memory retention.

Why does the display show 'E' or 'Error'?

This usually indicates overflow (result too large) or division by zero. Press the CE/C key to clear the error and start a new calculation.

How do I clear the memory?

Press MC (Memory Clear) to erase the stored value. You can also press CE/C twice to clear the current calculation and any pending operations.

Does the calculator work without battery if there is light?

Yes, the solar cell powers the calculator in sufficient ambient light. In low light, the battery backup takes over. If the display becomes dim, replace the battery.

How do I calculate a percentage?

For example, to find 10% of 200: type 200, press x, type 10, press %. The result (20) will appear. For add-on or discount, use + or - after the percentage.

What is the auto power-off time?

The calculator automatically turns off after approximately 7 minutes of inactivity to save battery. Press ON/C to turn it back on.

Can I reset the calculator to factory settings?

There is no dedicated reset. Removing the battery for a few seconds will clear all memory and reset the calculator. Reinsert the battery to restart.

How do I use the square root function?

Enter the number, then press the √ (square root) key. The square root of the displayed number will appear instantly.

Is this calculator suitable for advanced math?

No, the EC240 is a basic calculator for simple arithmetic, percentages, and square roots. It does not have trigonometric, logarithmic, or statistical functions.

How should I clean the calculator?

Use a dry, soft cloth to wipe the exterior. Do not use water, cleaning agents, or abrasives. Keep the calculator away from dust and liquids.

USER MANUAL EC240 AURORA

Please use the calculator in good lighting conditions.

Auto Power Off

If the calculator is not used for a period of 6-10 minutes, the unit will automatically switch off.

Calculation Examples:
□ Basic calculation

PROBLEM	INPUT	DISPLAY
2+3-1=4	2 + 3 - 1 =	4.
-2.4×6÷8=-1.8	2. 4 + 6 ÷ 8 =	-1.8
2×(3+4)-5=9	3 + 4 2 - 5 =	9.
3×2.54=7.62	2 3 2. 5 4 =	7.62
2+3=5	2 + 3 =	5.
4+3=7	4 =	7.
2-3=-1	2 - 3 =	-1.
4-3=1	4 =	1.
2×3=6	2 3 =	6.
2×4=8	4 =	8.
2÷4=0.5	2 ÷ 4 =	0.5
3÷4=0.75	3 =	0.75

2+3+3=8	2+3=	8.
6-2-2=2	6-2=	2.
2^1=8	2X=	8.
20×25%=5	20X25%	5.
5÷20%=25	5÷20%	25.
20×(1+15%)=23	20+15%	23.
20×(1-20%)=16	20-20%	16.
2×3=6	2X3M+	M 6.
-) 3×4=12	3X4M-	M 12.
+) 4×5=20	4X5M+	M 20.
14		M 14.
		14.
3^2+4^2=5	3X3M+4X4M+
		M 5.

Producer

Aurora Electronics (UK) LTD.

Unit 1 & 2 Shires Industrial Estate

Lichfield, Staffordshire, WS14 9AZ, U.K.

www.aurora-ltd.co.uk