How to use mrc on UCAT calculator?

The MRC button on the UCAT calculator is used to recall a number from the calculator's memory. It works in conjunction with the M+ (Memory Plus) button, which adds a number to the memory. This functionality is particularly useful for calculations where you need to reuse the same number multiple times without re-typing it, such as when dealing with complex powers or multi-step equations.

Understanding the Memory Function

The UCAT calculator includes a simple memory function, allowing you to store and retrieve a single numerical value.

• M+ (Memory Plus): This button adds the currently displayed number to the calculator's memory. If there's already a number in memory, the new number is added to it.
• MRC (Memory Recall/Clear): This button has a dual function:
  • Pressing it once will recall the number currently stored in memory and display it on the screen.
  • Pressing it a second time (after recalling) will clear the number from the calculator's memory.

Step-by-Step Usage of M+ and MRC

Here’s a practical guide on how to use these memory functions:

1. Store a number in memory (using M+):

   • Type the number you wish to store (e.g., 17.8).
   • Press the M+ button. You'll typically see an "M" symbol appear on the calculator display, indicating a number is now stored in memory.

2. Perform other calculations (optional):

   • You can now clear the screen (usually with the AC or C button) and perform other calculations. The number stored in memory remains untouched.

3. Recall the stored number (using MRC):

   • When you need to use the stored number in your current calculation, press the MRC button once. The stored number will instantly appear on the display, ready to be used in your calculation.

4. Clear the memory (using MRC again):

   • After recalling the number, if you press MRC a second time, it will clear the memory. The "M" symbol on the display will disappear, indicating the memory is now empty. This is important to do before storing a new number for a new calculation, to avoid adding to a previous value.

Practical Applications and Examples

The memory function can significantly speed up your calculations and reduce errors, especially in complex scenarios.

Example: Reusing a Base for Powers

Imagine you need to calculate (17.8)^2 + (17.8)^3. Instead of typing 17.8 multiple times:

1. Store the base:

   • Type 17.8.
   • Press M+. (Now 17.8 is in memory).

2. Calculate the first power:

   • Press MRC (recalls 17.8).
   • Press x (multiplication).
   • Press MRC (recalls 17.8 again).
   • Press = (result is 17.8^2).
   • Press M+ (to add this result to the memory, which now holds 17.8 + 17.8^2. Correction: This specific example is tricky. If the intent is 17.8^2 + 17.8^3, you would calculate each term and then sum them, possibly using memory for the intermediate sum, or simply for the base number.)

Let's refine the example for clarity: Calculating multiple expressions involving the same base.
Suppose you need to evaluate: (17.8 * 5) + (17.8 / 2).

1. Store the common number:

   • Type 17.8.
   • Press M+. (17.8 is now in memory, indicated by 'M' on display).

2. Calculate the first term:

   • Press MRC (recalls 17.8).
   • Press x.
   • Type 5.
   • Press = (result is 89).
   • To save this intermediate result for later summation: Press M+ again. (Now memory holds 17.8 + 89). Or, more simply, just write it down if the expression is short.

3. Calculate the second term:

   • Clear the display (AC).
   • Press MRC (recalls 17.8).
   • Press / (division).
   • Type 2.
   • Press = (result is 8.9).

4. Sum the results:

   • Take the result from step 2 (89) and add it to the result from step 3 (8.9).
   • 89 + 8.9 = 97.9.

Using MRC for a cumulative sum:
If you had a long list of numbers and needed their sum, you could:

1. Enter the first number, press M+.
2. Enter the second number, press M+.
3. Repeat for all numbers.
4. Press MRC once to recall the total sum.

Mastering the use of the M+ and MRC buttons can significantly enhance your efficiency and accuracy when tackling complex calculations in the UCAT exam, helping you save valuable time.