How to Put Percent in Calculator Ti-84

Basic Percentage Entry

Entering percentages on your TI-84 is straightforward. Here's how to do it:

1. Press the 2ND key (the small key above the MODE key).
2. Press the % key (located above the DEL key).
3. Enter your percentage value (e.g., 15 for 15%).
4. Press ENTER to store the percentage.

Percentage Calculations

Perform percentage calculations with these steps:

1. Enter the base number (e.g., 200).
2. Press the 2ND key, then the % key.
3. Enter the percentage value (e.g., 15).
4. Press ENTER to see the result (200 × 0.15 = 30).

For percentage increases or decreases:

1. Enter the original value (e.g., 100).
2. Press the + or - key.
3. Press the 2ND key, then the % key.
4. Enter the percentage change (e.g., 20).
5. Press ENTER to see the result (100 + 20% = 120 or 100 - 20% = 80).

Percentage Functions

The TI-84 has several built-in functions for percentage calculations:

• Percent of: Use the 2ND + % sequence as shown above.
• Percentage Increase/Decrease: Use the + or - keys with the percentage.
• Percentage Change: Use the formula (New Value - Original Value)/Original Value × 100.

Using Percentages in Graphing

To use percentages in graphing functions:

1. Press Y= to access the function editor.
2. Enter your function (e.g., Y1 = 0.15X).
3. Press GRAPH to view the linear relationship.

For exponential growth/decay with percentages:

1. Use the exponential function: Y1 = a(1 + r)^x.
2. Where 'a' is the initial amount and 'r' is the percentage rate (e.g., 0.15 for 15%).

Common Mistakes

Avoid these common percentage entry errors:

• Forgetting to press 2ND before the % key.
• Entering percentages as whole numbers without converting to decimals.
• Not pressing ENTER after entering the percentage value.
• Confusing percentage points with percentages (e.g., 5% vs. 5 percentage points).