L3.6: Simple Interest

L3.6: Simple Interest

Page 179

I can statements

• ​I can identify what each variable means in the simple interest formula​​​

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• I can find the value of one variable given the value of the others​

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• ​I can relate simple interest to real-world applications

Open Ended

What do you think an interest is?

​I = Prt

I: interest

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P: principal

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r: interest rate (%)

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t: time​ (in years)

​Sam deposits $640 into his new savings account, with a simple interest rate of 12.5% per annum.

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a) What is the simple interest that he earns after 3 years?​

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b) What is the simple interest that he earns after 6 months?​

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c) What is the amount in his savings account after 3 years?

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​Charles deposits $10,000 into his new savings account, with a simple interest rate of 18% per annum.

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a) What is the simple interest that he earns after 7 years?​

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b) What is the amount in his savings account after 7 years?

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Draw

​Charles deposits $10,000 into his new savings account, with a simple interest rate of 18% per annum.

a) What is the simple interest that he earns after 7 years?​

b) What is the amount in his savings account after 7 years?

IXL | Simple interest | 8th grade math

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​Sam earns $192 simple interest after 4 years, at an interest rate of 6% per annum.

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a) What is the original amount of money that he started with? (a.k.a. "principal")​

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​Jill earns $49.86 simple interest after 6 years, at an interest rate of 3% per annum.

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a) Find the principal.​

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​Sam earns $20 simple interest after 20 months, at a rate of 2% per annum.

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a) Find the principal.

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Multiple Choice

Find the rate when

Principal = $350

Time = 2.5 years

Simple interest = $140

• 1%

• 16%

• 100%

• 3.5%

Multiple Choice

Find the rate when

Principal = $9,600

Time = 3 months

Simple interest = $72

• 400%

• 4%

• 3%

• 33%

Multiple Choice

Find the time when

Principal = $500

Rate = 7.5% p.a. (per annum)

Simple interest = $150

• 2 years

• 3 years

• 4 years

• 5 years

Multiple Choice

Find the time when

Principal = $700

Rate = 13% p.a.

Simple interest = $78

• $$\frac{3}{4}$$  year

• $$\frac{11}{13}$$  year

• $$\frac{5}{8}$$  year

• $$\frac{6}{7}$$  year

Draw

Answer the question below

Draw

Answer the question below