I have used the calculator for so many years. Have you used other keys except + - * / and numeric keys?
Because the display screen of an ordinary calculator is simple and does not have bracket function keys, it means that the priority order of the four calculations cannot be distinguished, and it can only be calculated from left to right.
So the computer designers added a class of function keys to solve this problem.
To facilitate understanding of subsequent content, we will first simply divide the calculator into front desk (numbers displayed on the display) and back desk (numbers that cannot be seen)
Function key classification:
1. MEMORY categories: M+, M-, MRC (MR, MC)
MR (memory recall, read storage): It is to map the stored information to the display screen that is being computed.
MC (memory clear, clear storage): means clearing storage information. Some calculators do not have these two keys, only one MRC, which is actually a combination of these two keys. Press once is MR, and press again is MC.
M+ (memory, memory storage addition operation): either stores the numbers displayed on the display to the background of the calculator, or stores the calculation results of the display + - * / to the background.
Example: When the calculator is turned on, enter the number 2, then press M+, (the display screen will display the MEMORY prompt) and press other numbers such as 666, press MR, and the display screen will display the number 2.
When powering on, enter 1+1, M+, and the number 2 stored in the background is.
M-(memory-): It is to perform subtraction operations based on the original stored information.
Comprehensive use of M+, M- and MR: Calculate 1x2-2x3
1x2, M+ (2 of the calculation result of 1x2 in the background)
2x3, M- (The background uses the calculation result 2 stored in the previous step to subtract the calculation result 6 of 2x3, and obtains the calculation result -4 and stores it in the background.)
MR (display calculation result-4)
Exercise: 26x20+25x31.76 (result 1314)
2. GT key
GT key (grand total): Press the GT key to display the GT results calculated in the background on the display screen, and press the AC or C key to eliminate the GT display logo.
GT: GT=Grand Total, that is, all the numbers obtained after pressing the equal sign are accumulated and added to be stored in the background. Press GT to display the cumulative number, and press again to clear.
Example: 1x1+2x2+3x3 (Result 14)
Key order: AC, 1x1=, 2x2=, 3x3=, GT
3. MU key
The key MU(mark-up and mark down) is mainly used in finance.
Price increase calculation: What is the 5% increase in 60? (60x5 MU = 63)
Calculate the rate of change: 80 to 100, find the rate of growth? (100-80 MU = 25)
Selling price calculation: The cost is 60, the expected profit margin is 25%, what is the sales price? (60÷25 MU = 80, profit is just press more MU: 20)