Fractions and Mixed Numbers on the TI-84
Does my calculator have “MathPrint” features?
Press ALPHA Y= . They’re both in the upper right-hand area of the keypad.
1:
2:
3:
4:
n/d
Un/d
►n/d◄ ►Un/d
►F◄ ►D
If you get this menu, then yes, you have MathPrint and
this is the correct handout you need.
If you have a TI-84 but you don’t see this menu, ask your
instructor for assistance in upgrading your calculator to the
newest software. The TI-83 methods will work but you really want to upgrade.
If you have a TI-83, you have to use other methods. Get a different handout for
help with doing fractions and mixed numbers on the TI-83 calculator.
How do I type a fraction?
1) Press ALPHA Y= 1 for n/d. The calculator gives
you a fraction picture with empty boxes.
2) Type the numerator in the top box.
3) Press the down arrow.
4) Type the denominator in the bottom box.
5) Press the right arrow to get out of the fraction.
Try it: Type the
3
fraction .
4
Press ENTER. The
calculator echoes
the fraction.
How do I type a mixed number?
1) Press ALPHA Y= 2 for Un/d. The calculator gives
you a mixed number picture with empty boxes.
2) Type the whole number in the whole number box.
3) Press the right arrow to move to the numerator
box.
4) Type the numerator; press down arrow; type the
denominator.
5) Press the right arrow to get out of the fraction.
How do I reduce a fraction?
Type the fraction. If it can be
reduced, the calculator will
reduce it. If it cannot be
reduced, the calculator gives
you back the same fraction
again.
Try it: Type the fraction
Try it: Type the
3
mixed number 2 .
4
Press ENTER. The
calculator echoes
the equivalent
improper fraction
11
.
4
12
30
and press ENTER.
2
The calculator reduces it to . Try it again
4
5
with the fraction . It echoes back the same
4
7
fraction since is already in lowest terms.
7
For TI-84 calculators that have newer software that supports MathPrint. 5/30/2016 8:21 PM D.R.S.
How do I convert improper fractions to
mixed numbers?
1) Type the fraction or the mixed number
that you want to convert. And do not
press ENTER yet!
2) Press ALPHA Y= 3 for ►n/d◄ ►Un/d.
That’s the calculator’s picture for
“fraction to mixed.
Try it:
What about the other way? Mixed
number to improper fraction?
Unfortunately, that’s different! Just type the
mixed number and press ENTER. The
calculator converts it to an improper fraction.
and press ENTER. The
calculator converts it to the
Type the improper fraction
38
7
and press ALPHA Y= 3 then
ENTER. The calculator converts
3
it to 5 .
7
Type the mixed number 19
improper fraction
79
4
3
4
.
How do I rewrite a fraction in higher terms? (“Un-reducing”)
3
?
4
20
For example, a problem might ask us to rewrite =
3
, to find the numerator that
changes into an equivalent fraction whose denominator is 20.
4
The by-hand way is to think “4 goes into 20 = 5
times, and 5 times 3 = 15, so the second fraction is
15
3 5
15
20
4 5
20
.” Or we think of it as ∙ =
Try it:
Find the missing numerator:
.
5
?
=
6 42
A calculator way to do this is “cross multiply and
divide”: Multiply along the diagonal that has two
numbers, namely 20 ⋅ 3. Then divide by the
leftover number: ÷ 4. That gives us the 15.
Whichever method you use,
the correct answer is 35. So
5
35
6
42
another name for is
.
How do I do arithmetic problems?
Just type them in exactly the way they look in the original problem. If there are
parentheses in the original, type the parentheses using the buttons are above the
8 and 9. If there is an exponent 2, use the x2 button (it’s near the 7). If there is a
higher exponent, press the ^ (it’s above the ÷) then the exponent.
The answer is
Try it:
Try it:
Try it:
7 9
+
8 16
3
5
1 ×3
4
6
23
.
16
The answer is
161
24
(4 +
17
or 6 .
24
10
3
)÷3
11
11
3
1
2
2
The answer is or 1 .
For TI-84 calculators that have newer software that supports MathPrint. 5/30/2016 8:21 PM D.R.S.