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PRE-ALGEBRA
Lesson 1-8 Warm-Up
PRE-ALGEBRA
Lesson 1-8 Warm-Up
PRE-ALGEBRA
Reasoning Stategies: Look
For a Pattern (1-8)
How do you solve a
problem involving a
pattern?
To find a pattern: 1. understand what the problem is asking, 2. make a
plan to solve the problem, and 3. carry out your plan
Example: News spreads quickly at Luiseno. Each student who hears a
story repeats it 15 minutes later to two students who have not yet heard
it and then tells no one else. If the first student hears the news at 8:00
a.m., how many students will know the news by 9:00 a.m.
Step 1: Understand what the problem is asking
• 1st person hears news at 8 a.m.
• Every 15 minutes a person who heard news tells 2 more people and
no more
• How many people know story by 9 a.m.
Step 2: Make a table or a tree diagram to organize the numbers and
use it to find a pattern.
PRE-ALGEBRA
Reasoning Stategies: Look
For a Pattern (1-8)
Step 3: Carry out your plan.
Make a table.
To find the next number in the pattern, add the new students to the number
you had from before. As we can see, the pattern is to double the number
every fifteen minutes.
Make a tree
diagram.
By 9:00, 31 students will know the news.
PRE-ALGEBRA
Reasoning Strategy: Look for a Pattern
LESSON 1-8
Additional Examples
Each student on a committee of five students
shakes hands with every other committee member.
How many handshakes will there be in all?
The pattern is to add the number of new handshakes to
the number of handshakes already made.
4
the number of handshakes by 1 student
4+3=7
the number of handshakes by 2 students
PRE-ALGEBRA
Reasoning Strategy: Look for a Pattern
LESSON 1-8
Additional Examples
(continued)
Make a table to extend the pattern to 5 students.
Student
1
2
3
4
5
Number of original
handshakes
4
3
2
1
0
Total number of
handshakes
4
4+3
=7
7+2
=9
9+1
= 10
10 + 0
= 10
There will be 10 handshakes in all.
PRE-ALGEBRA
Reasoning Strategy: Look for a Pattern
LESSON 1-8
Lesson Quiz
Solve using any strategy.
1. You have a penny, a nickel, a dime, and a quarter. You give
away three coins. How many different amounts of money can
you give away? Name the values.
4; 16¢, 31¢, 36¢, 40¢
PRE-ALGEBRA