Enter and calculate with negative numbers
Use the negative-sign key (not the subtract key) so a number really becomes negative.
A negative sign and a subtraction sign are different things. Subtract takes one number away from another. The negative key flips the sign of one number.
Classic and Natural calculators have a separate (−) key for negative numbers. RPN calculators have a change-sign key that you press after the number.
Classic Graphing 84
Start on the main screen: Press 2nd then mode (QUIT) to get back to the home screen. Pressing clear on a menu also backs out of it.
Press the (−) key, then 4. Then the multiply key, the (−) key and 6.
(−)4×(−)6Press enter. A negative times a negative is positive. The small raised minus on the screen shows a negative number.
enter
You should see⁻4*⁻6 24
Natural Scientific 991
Start on the main screen: Press MENU, then 1 (Calculate) to return to the main calculation screen. AC clears the line you are on.
Press the (−) key, 4, multiply, the (−) key and 6.
(−)4×(−)6Press = to see 24.
=
You should see-4×-6 24
RPN Scientific 15
Start on the main screen: There is no menu to leave. Press the back arrow to clear a number you are typing, or CLx (g then back arrow) to clear the X register.
Key in 4 and press CHS to make it negative. Press ENTER to finish the number.
4CHSENTERKey in 6, press CHS, then multiply.
6CHS×
You should see24.0000
Press ENTER after CHS, or the next digits you type join the same number.
Tips
- Use the subtract key only between two numbers. Use the negative key at the start of a number or after an operator.