|
Activity #1: This activity will familiarize you with the keys that are used to create,add to or subtract from,recall and clear the calculator memory. |
Activity #1:
Our calculators have three memory keys:
M+ This key will add to the total stored in memory.
M- This key will subtract from the total stored in memory.
M
rc This is used to both recall and clear the memory contents.In Table 1 which follows a step by step procedure for entering and solving an addition problem by using the memory function keys is outlined. Comments describe what is happening inside the calculator.
Problem: Paul gets a CD for $18.95 and three tapes for $9.95 each. He also buys a poster for $15. How much money has he spent?
Step# |
Data |
Display |
Comments |
|
1 |
18.95 |
18.95 |
Cost of 1 CD |
|
2 |
Push M+ |
18.95 |
See Note 1 |
|
3 |
9.95 |
9.95 |
Cost of 1 CD |
|
4 |
X |
9.95 |
No Change |
|
5 |
3= |
29.85 |
Cost 3 Tapes |
|
6 |
Push M+ |
29.85 |
No Change |
|
7 |
15 |
15 |
See Note 1 |
|
8 |
Push M+ |
15 |
No Change |
|
9 |
Push MRC |
63.8 |
Change to $ |
|
TABLE 1
Memory Addition
Notes:
One: When the memory is accessed an 'M' will appear above the display.This indicates that the number on the display when the M+ key was pushed has been entered into the memory storage area.
Two: At this point we need to talk about estimating what the answer would be in case an error should occur while entering the data. To estimate the problem shown in table one we can round the cost of the CD to $20, the tapes to $10 and the poster at $15. Thus $20 + 3 x $10 + $15 = $65 (Estimate). The result using this estimate is $65. The actual answer is $63.80.
End of Activity #1.