Reteach and Skills Practice Workbook

3–4
Name
Reteach
Algebra: Find a Rule
Date
Sometimes math exercises have a pattern to the answers. Once you
find the pattern, you can make a rule that will solve the problem for
any input.
Use this problem to learn more about finding a pattern and making
a rule:
4AF1.5
Chapter Resources
No matter how many cards Emma has, James always has five
more cards.
This problem tells you the rule: Emma’s cards + 5 = James’ cards. If
Emma has 15 cards, how many cards will James have? James will have
15 + 5, or 20 cards.
Now see the same problem written a different way.
Copyright © Macmillan/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Emma’s Cards
Input (x)
3
5
7
9
Practice
James’ Cards
Output (y)
8
10
?
?
1. Identify the pattern: 3 + __ = 8
5 + __ = 10
The pattern is to add 5 to each number.
2. Identify the rule and write it as
an equation.
x + 5 = y
So the next numbers in the table
are 12 and 14.
Write each rule as an equation to describe the pattern. Then use the
equation to find the next three numbers in the pattern.
1.
Rule:
Input (d )
4
8
12
16
20
Output (e)
8
12
2.
Rule:
Input ( j )
2
5
8
11
14
Output (k)
11
14
Grade 4 45 Chapter 3