Math 3 Standard 3 Combo
12/26/02
3:27 PM
Page 157
Standard Indicator
3.3.6
Function Machine
Purpose
Students will solve simple problems involving a functional relationship
between two quantities by using a “function machine.”
curriculum
Materials
For the teacher: medium-size cardboard box, construction paper, blank
3" × 5" index cards, blank 81/2" × 11" paper, tape
For each student: copy of Black Line Master (BLM) Function
Machine Fun
A. Pre-Activity Preparation
1. Create a “function machine” from a cardboard box.
a. Cut the back of the box open for ease of operation.
b. Cover the sides and front of the box with construction paper.
c. Cut a slit in the left and right sides of the box. Make the slit
large enough for the index cards to slide through easily.
2. Prepare the index cards with several “input” numbers on which to
perform the functions as well as the numbers that will be “output”
when the function is performed (e.g., if the function is “× 2,” you
might input 2, 18, 35 and output 4, 36, and 70). Use four or five
different functions that include a variety of arithmetic operations.
3. Write the function “× 5” on an 81/2" × 11" piece of paper and tape
it to the front of the “function machine.”
B. Student Activity
1. Show the class the “function machine” and tell students its name.
2. Tell students that when you put a number into this machine, the
function changes the number into a new number by performing
an arithmetic operation on it.
3. Explain that an arithmetic operation might include subtraction,
addition, multiplication, or division (as well as other operations
that they have not learned yet).
4. Tell the class that the first function the machine will perform
is “× 5.”
5. Explain to students that whatever number is placed into the
machine, the “input,” will be multiplied by five and that a new
number, the “output,” will come out of the machine.
(continued)
Visual Arts
Have students create
their own function
machines from
shoeboxes and
construction paper.
Allow them to decorate
them and use them in
a partner activity.
extending
THE
ACTIVITY
Place the function
machine in a learning
center. Have students
create their own
functions. Have students
practice placing
numbers into the
machine and writing the
results on the index
cards. Students can then
match input numbers,
functions, and output
numbers.
Standards Links
3.2.1, 3.2.5, 3.6.3
page 157
Standard 3
Activity
Standard 3 / Curriculum Framework / Activity 5
Indiana Mathematics Grade 3 Standards Resource, February 2003
connecting
across the
Math 3 Standard 3 Combo
12/26/02
3:27 PM
Page 158
Activity (continued)
Standard 3
6. Show the class the first number that will be put into
the machine.
7. Place the number into the machine and ask the class if they
know what number will come out of the machine.
8. Pull the correct answer from the machine and show it to
the class.
9. Replace the “× 5” function sign with a new function sign. Repeat
the procedure with the new function.
10. Replace that function sign with a blank 81/2" × 11" piece of paper.
11. Tell students that you will be putting a few numbers into the
“function machine” and pulling out the results. Tell students to
be thinking about what the function might be.
12. Put in a number and pull out the result. Ask students if they
know the function. Write students’ guesses on the blank
81/2" × 11" piece of paper.
13. Test answers by putting another number into the machine and
pulling out the result. Ask students if the result is correct for the
function on the front of the box. If it is not, replace that function
sign with a different one. Continue in this manner until a correct
function is given and confirmed.
Questions for Review
Basic Concepts and Processes
During the activity, observe students’ answers on the BLM Function
Machine Fun and ask the following questions:
What number will come out of the function machine if “6” is
placed into it and the function is “times 10?”
How did you get your answer?
What is the answer to the problem “6 × 10?”
If the function is “add 9,” tell me a number you would put into
the function machine and give me the number that would come
out of it.
page 158
Standard 3 / Curriculum Framework / Activity 5
Indiana Mathematics Grade 3 Standards Resource, February 2003
Math 3 Standard 3 Combo
12/26/02
3:27 PM
Page 159
Name:
Function Machine Fun
Solve the problems below by using the function machine idea.
What number would come out of the function machines below?
Write the answer on the paper leaving the machine.
×2
4
188
− 33
Using the function machines above,
find the missing numbers and write them below:
Number going
into machine
8
12
Number coming
out of machine
Number going
into machine
235
50
14
Number coming
out of machine
158
Find the missing functions from the function machines below.
Write the function on the front of the function machines:
38
23
23
Number going
into machine
5
51
130
4
16
Number coming
out of machine
20
66
145
Standard 3 / Curriculum Framework / Activity 5
Indiana Mathematics Grade 3 Standards Resource, February 2003
Number going
into machine
32
40
4
Number coming
out of machine
8
10
1
Black Line Master 1
page 159
Math 3 Standard 3 Combo
12/26/02
3:27 PM
Page 160
Function Machine Fun
Teacher Directions
Distribute the BLM Function Machine Fun. Have the students find the missing numbers and
functions from the function machines pictured. Instruct them to write the numbers on the
function machine pictures or in the tables as instructed.
Answer Key
155
155
8
×2
4
188
− 33
Using the function machines above,
find the missing numbers and write them below:
Number going
into machine
Number coming
out of machine
Number going
into machine
Number coming
out of machine
8
12
7
16
24
14
235
50
191
202
17
158
Find the missing functions from the function machines below.
Write the function on the front of the function machines:
38
23
23
Number going
into machine
5
51
130
Black Line Master 1
page 160
+15
Number coming
out of machine
20
66
145
4
16
Number going
into machine
32
40
4
÷4
Number coming
out of machine
8
10
1
Standard 3 / Curriculum Framework / Activity 5
Indiana Mathematics Grade 3 Standards Resource, February 2003