Research at least two lending institutions for the interest rate for both a 15-year and a 30-year fixed rate mortgage with no “points” or other variations on the interest rate for the loan.

Buying a House

  1. Select a house from a real estate booklet, newspaper, or website. Find something reasonable – between $100,000 and $350,000. Cut out the picture and/or description of your chosen house and attach it to this project. Assume that you will pay the asking price for your house.

Listed selling price: Click or tap here to enter text.

  • Assume that you will make a down payment of 20%.

Down payment: Click or tap here to enter text.

Amount of the mortgage: Click or tap here to enter text.

  • Research at least two lending institutions for the interest rate for both a 15-year and a 30-year fixed rate mortgage with no “points” or other variations on the interest rate for the loan.
    • Name of first lending institution: Click or tap here to enter text.
      • Rate for 15-year mortgage: Click or tap here to enter text.
      • Rate for 30-year mortgage: Click or tap here to enter text.
    • Name of second lending institution: Click or tap here to enter text.
      • Rate for 15-year mortgage: Click or tap here to enter text.
      • Rate for 30-year mortgage: Click or tap here to enter text.
  • Assuming that the rates are the only difference between the different lending institutions, find the monthly payment at the better interest rate for each type of mortgage.
    • 15-year monthly payment: Click or tap here to enter text.
    • 30-year monthly payment: Click or tap here to enter text.

**REMEMBER: These payments cover only the interest and the principal on the loan. They do not cover the insurance or taxes.

To organize the information for the amortization of the loan, construct a schedule that keeps track of:

  • The payment number and the month/year.
  • The amount of the payment.
  • The amount of interest paid.
  • The amount of principal paid.
  • The remaining balance.

Although there are many programs online available for this, a Microsoft Excel spread sheet and Google Sheets are most widely used.

Loan Amortization Schedule

Loan Amortization Tutorial

Excel Loan Amortization Template

Google Sheets Loan Amortization Template

Copy and paste a screen shot or link out to your completed amortization table below:

It’s not necessary to input all of the payments. Fill in the sample of payments in the following schedules, and answer the questions after each table.

15 year mortgage:

Payment NumberPayment Amount ($)Interest Paid ($)Principal Paid ($)Remaining Balance ($)
1.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
2.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
50.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
90.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
120.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
150.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
180.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.$0.00.
totalClick or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.– – – – – – – – –

Use the proper word or phrase to fill in the blanks.

  • The total principal paid is the same as the Click or tap here to enter text.
  • The total amount paid is the number of payments times Click or tap here to enter text.
  • The total interest paid is the total amount paid minus Click or tap here to enter text.

Use the proper number to fill in the blanks and cross out the improper word in the parenthesis.

  • Payment number Click or tap here to enter text. is the first one in which the principal paid is greater than the interest paid.
  • The total amount of interest is $Click or tap here to enter text. (more or less) than the mortgage.
  • The total amount of interest is Click or tap here to enter text. % (more or less) than the mortgage.
  • The total amount of interest is Click or tap here to enter text.% of the mortgage.

30 year mortgage:

Payment NumberPayment Amount ($)Interest Paid ($)Principal Paid ($)Remaining Balance ($)
1.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
2.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
60.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
120.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
240.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
300.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.
360.Click or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.$0.00.
totalClick or tap here to enter text.Click or tap here to enter text.Click or tap here to enter text.– – – – – – – – –
  • Payment number Click or tap here to enter text. is the first one in which the principal paid is greater than the interest paid.
  • The total amount of interest is $ Click or tap here to enter text. (more or less) than the mortgage.
  • The total amount of interest is Click or tap here to enter text.% (more or less) than the mortgage.
  • The total amount of interest is Click or tap here to enter text.% of the mortgage.

Suppose you paid an additional $100 a month towards the principal:

  • The total amount of interest paid with the $100 monthly extra payment would be $ Click or tap here to enter text.
  • The total amount of interest paid with the $100 monthly extra payment would be $Click or tap here to enter text. (more or less) than the interest paid for the scheduled payments only.
  • The total amount of interest paid with the $100 monthly extra payment would be Click or tap here to enter text.% (more or less) than the interest paid for the scheduled payments only.
  • The $100 monthly extra payment would pay off the mortgage in Click or tap here to enter text. years and Click or tap here to enter text. months; that’s Click or tap here to enter text. months sooner than paying only the scheduled payments.

Reflection/Discussion:

Reflect on and summarize what you have done and learned through your work on this project. Because this is a math project, you must compute and compare numbers, both absolute and relative values, that haven’t been compared above. Statements such as “a lot more” and “a lot less” do not have meaning in a college level course.

Make the necessary computations and compare:

(1) The 15-year mortgage payment to the 30-year mortgage payment,

(2) The 15-year mortgage interest to the 30- year mortgage interest,

(3) The 15-year mortgage to the 30-year mortgage with an extra payment, and

(4) The 15-year mortgage to the 30-year mortgage with a large enough extra payments to save 15 years and have the loan paid off in 15 years.

Also, know that the numbers don’t explain everything. What other factors must be taken into account when considering a mortgage?