HP 39g hp 39g+ (39g & 40g)_mastering the hp 39g+_English_E_F2224-90010.pdf - Page 45

Storing and Retrieving Memories Each of the alphabetic characters shown in orange below the keys can function as a memory. Some examples of this are shown in the third and fourth examples above where the values of 1, -3 and -4 are stored into A, B and C and the value of 3 is stored into X. All of this 'storing' of values is done with the key, which is one of the screen keys listed at the bottom of the HOME view. There are ways of obtaining even more memories than these 26 alphabetic ones, such as storing values into a list (see page 176), but 26 is enough for most people. Once stored into memory, a value can be used in a calculation by typing the letter into the place where you would normally use the value. Typing a letter and pressing ENTER will display memory's contents. There is an advantage to storing results in memories, particularly if they are long decimals, or if you're going to be re-using the result a number of times. 2 + 4× (−3) As an example, we will perform the calculation of 5. 2⋅3−5 We will do this in two stages, calculating the top and bottom of the fraction and storing the results in memories. Firstly the top of the fraction, storing the result in memory A, then the bottom, storing in B. And then finally the result... 45