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The below calc button is not responding - Casio Fx-991es Scientific Calculator

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The calculation may be taking too long and you got impatient. To reduce the time it takes to calculate some expression or find a root you can make better guesses (initial values), or choose better limits to an integral, or divide the integral in two if integrand symmetrical. If you can select the tolerance (error you are willing to accept), increase it: Instead of taking epsilon =1E-9, take epsilon=1.E-5. But that depends on the context of the calculations. You be the judge.

Posted on Dec 21, 2013


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It's the fraction button. It lets you enter a fraction as a numerator and a denominator.

Posted on Nov 27, 2013

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The Calc-Clean function removes scale and impurities.

To do so, set the steam control to position '0', set the temperature dial to 'MAX', and fill water tank up to the 'MAX' level. Then heat up the iron until the pilot light on the handgrip goes out.

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Move the iron forwards and backwards while boiling water/steam squirt from the holes in the soleplate to wash away impurities/scales.

When the water tank is empty, heat up the iron to dry it.

Finally move the iron to and fro on a piece of cloth to dry the soleplate. Repeat the process if necessary

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