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How to use units in a calculation on a TI-89 Titanium

By E-Code · updated

Give each number its unit (◆ MODE types _): 5_N*2_m ENTER gives 10.·_J, since the units multiply too. Add 2nd MODE (▶) and another unit such as _ftlb to convert the answer: 7.37562·_ftlb.

Step by step

  1. Type 5_N*2_m. 5 ◆ MODE ALPHA 6 × 2 ◆ MODE ALPHA 5 Type 5, ◆ MODE for _, ALPHA 6 for n, then *2, ◆ MODE and ALPHA 5 for m. Unit names can be typed in either case.
  2. Work it out. ENTER Press ENTER. The units multiply too: newtons times metres is joules.
  3. Keep the line. ▶ Press ▶ to put the cursor at the end of the last entry.
  4. Add ▶_ftlb. 2nd MODE ◆ MODE 2nd ALPHA | T 4 ( ALPHA Press 2nd MODE for ▶, ◆ MODE for _, then 2nd ALPHA to lock letters, f t l b (| T 4 (), and ALPHA to unlock.
  5. Convert it. ENTER Press ENTER.
  6. Read the answers. 5 N × 2 m = 10 J of work, which is 7.37562 foot-pounds. Put units on every number and the TI-89 keeps track.

What the screen shows

5 N × 2 m = 10 J of work, which is 7.37562 foot-pounds. Put units on every number and the TI-89 keeps track.

Look for 7.37562·_ftlb on the screen.

Try it with the keys lit up

This guide is one of E-Code's Learn lessons. Open it on E-Code's TI-89 calculator and each key lights up in turn as you press it.

Try “Use units in a calculation” on the TI-89 calculator

Related

Physics programs for the TI-89 Titanium:

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