Math: Constant Calculations on the TI-30XA

Tutoring math, you handle all kinds of calculators.  The math tutor continues with constant calculations:  this time, we hear Texas Instruments’ side of the story.

The TI-30XA is extremely similar to the calculator I used in high school twenty five years ago.  It’s such a good design, why change it?  Similar to the Casio fx-260Solar (mentioned in my last article), it’s reverse entry.  That is, to get the square root of a number, you enter the number first, then key for square root.  Same goes for trig functions:  to get sin30°, you enter 30 first, then press sin.

Recall from my last article that constant calculations are convenient when you’re doing the same operation with the same number repeatedly. For example, let’s say you’re converting masses in kilograms to weights in pounds, so you’re multiplying by 2.2 repeatedly. Let’s imagine the first mass you must convert is 30kg. You can enter 30 X2.2 2nd HYP =. Now, a K appears at the top right corner of the screen; it signifies that you have entered a constant. (Notice the yellow K above the HYP key.)

As the TI-30XA manual states: “a constant is a number with an operation.” Our constant is “multiply by 2.2”. Now, if you enter a number and then press =, the calculator will give the number multiplied by 2.2; entering 10 and pressing = gives 22.

Pressing ONC cancels the constant. Or else, you can just press any of the arithmetic keys (+,-,x, or ÷) to cancel the constant.  You’ll know when you have; the K will disappear from the top right of the screen.

For more calculator hints, please come back:)

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

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