3.1: What’s My Rule?
Mental Math
Solve the fact problems.
Write your answer on your slate.
30 + 50 =
80 - 40 =
42 + 20 =
75 - 20 =
98 + 22 =
66 – 41 =
Math Message
Each person in the United States uses about 50 gallons
of water per day. Use this information to complete the
“What’s My Rule?” table in your notebook.
In
(days)
1
6
10
30
365
Out
(gallons)
50
300
500
1,500
18,250
What is the rule? X 50
In
(days)
1
6
10
30
365
Out
(gallons)
50
300
500
1,500
18,250
What do the numbers in the in (input) column
represent?
What do the numbers in the out (output) column
represent?
How are the input and output columns related?
Variations of the “What’s My Rule” Routine
Rule
Rule
Rule
Subtract 15
Add 100
Multiply
by 7
_________
In
30
90
65
110
Out
In
15
250
75
20
15
565
95
321
Out
350
120
665
421
In
7
2
9
600
Out
49
14
63
4,200
Other variations of “What’s My Rule?”
Rule
Rule
Divide by 6
A pound of nuts
cost $3.75
In
54
42
24
600
Out
9
7
4
100
Pounds
1
2
5
Cost
$3.75
$7.50
$18.75
11
$41.25
Math Journal page 53
Do #1-2 on
your own.
Do #3-6 with
your math
partner.
Wrap it UP!
• Fill in this “What’s My Rule” table
Rule
Divide by 4
In
100
16
24
Out
25
4
12
3
4
1
6
Tonight’s Homework
ALSO:
Put initials on and cut out
your x, / triangles (activity
sheets 1-4 in math journal).
Bring back to school
tomorrow.
Math Boxes