Equations Lesson 6.12 Simple and Compound Interest.notebook
Interest • Students will calculate simple and compound interest earnings.
• Students will compare simple and compound interest.
Equations and Inequalities
Write an equation or inequality for the following.
TEKs
8.12 ­ Calculate and compare simple interest and compound interest earnings 1. The sum of a number and 13 is at least 27.
2. A number decreased by 5 is less than 33.
3. Thirty is no greater than the sum of a number and ­8.
ANSWERS
1. n+13>27
4.
2. n­5<33
Which inequality is NOT equivalent to x<12?
3. 30<n+(­8)
x­7<5
x+4<16
Title Page
answer
x­1<13
12>x
4. C
Warm Up
Practice Answers
c + m < 500
Maintain Your Skills
1. 3; y = 3x + 4
2. 2; y = 2x + 6
3. 1; y = x + 2
Practice Answers
What are the differences in the graphs?
Why did the student get upset when Ma
th
his teacher called him average?
H
um
o
r
c
It was a 'mean' thing to say! Math Humor
Launch
1
Equations Lesson 6.12 Simple and Compound Interest.notebook
Cut and tape Labsheet in your journal.
1.
2.
Find a Friend
Harry received $500 to open a savings account that earns 5% of the original deposit each year.
Harry plans to leave the money in the account for at least 5 years. Complete the table below. Round any interest earned to the nearest penny.
Barry received $500 to open a savings account that earns 5% of the initial deposit in the first year, and then 5% of the prior year’s ending balance for every year after the first year. Barry plans to leave the money in the account for at least 5 years. Complete the table below. Round any interest earned to the nearest penny.
3.
How much does Harry have after 5 years? _____________________
4.
How much does Barry have after 5 years? _____________________
Find a friend and tell them the difference
between simple and compound interest
Labsheet
Find A Friend
______
Date
Swim in the ocean with a hungry shark...
or walk in the jungle with a hungry lion?
Simple and Compound Interest
• simple interest formula is:
1. What is simple interest?
I = P x r x t
P ~ principal r ~ rate t ~ time
(years)
• then add interest to the Principal to get total
Total = P(1 + rt)
Would You Rather?
2. What is compound interest?
Notes
• compound interest formula is:
Total = P(1 + r)t
P ~ principal r ~ rate t ~ time
(years)
• to find the interest, take the total and subtract the Principal:
Practice
Simple and
Compound Interest
Worksheet
I = Total ­ P
Notes
Homework
2
Equations Lesson 6.12 Simple and Compound Interest.notebook
Closing Questions
How do you find simple interest? (I = Prt)
What does the P stand for in the equation? I = Prt (Principal)
Closing Questions
3