After performing a sequence of calculations in S-V.P.A.M. Series, when I attempt to store the answer in memory, the value changes to something else altogether.
A7
If you perform a simple two-step operation, then after pressing the [=] key, you can press [SHIFT] [STO] [M] to store the answer into memory.
Example: 9-2, press [=] and the answer is 7, then press [SHIFT] [STO] [M] and 7 is stored in memory.
If you perform additional calculations after that (using the answer from the previous calculation), then the calculator will begin using answer memory (as seen by Ans on the display). When you are finished with the calculation, and press [SHIFT] [STO] [M], it will repeat the last calculation and store its result into memory instead.
Example: 3×3, press [=] and the answer is 9. Then press [-] [2] [=] to subtract 2 from that answer, and the new answer is 7. Then press [SHIFT] [STO] [M], and 5 is stored in memory (because it subtracted 2 from the 7 that was in answer memory).
If you perform multiple calculations in sequence and have an answer that you want to store in memory, press [Ans] followed by [SHIFT] [STO] [M].
This may also apply to other calculators in S-V.P.A.M. series, such as fx-991MS.
