Assignment 1: Variables, print, input, operators

CSCI 141
Assignment 1: Variables, print, input, operators
Introduction
This first homework has 2 parts. For the first part please answer the questions on Canvas
assigned for this homework, and for the second portion you will complete a single programming
task.
1 Questions: 16 points
Please answer the questions in the A1 Written quiz on Canvas. The questions on Canvas have
been configured so that there is no time limit, but you have only 2 attempts to submit your
answers. The score that is recorded in Canvas is the score that is the latest (most recent
submission) of your attempts.
2 Programming Task: 20 points
Congratulations! You’ve just been hired as a Python programmer at an education start-up
company. Your first task is to develop a prototype of a program that kindergarten students will
use to check their homework assignments which involve addition, multiplication, and division
problems.
Program Specification
The program begins with a series of prompts, then prints a few lines to the screen in response.
In total there are 6 lines that are printed each time the program is run:
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1. Prompt the user for their name
2. Greet the user and ask them to supply the first integer
3. Prompt the user for a second integer
4. Output the sum of the two numbers
5. Output the product of the two numbers
6. Rephrase the division question, and output the whole number and remainder. All numerical outputs on the 6th line of output must be integers (whole numbers, without
decimals).
A sample invocation of the program is shown in Figure 1:
Figure 1: Sample Output
Although this is a simple set of steps, there are many, many different Python programs that
can achieve it. The text of your prompts does not need to match the example exactly. However,
your solution must follow the the instructions above exactly as specified. For example:
• Both the greeting and the prompt for the first number must be printed on the second line
of output.
• The last (6th) line of output must rephrase the division question and output the whole
number and remainder portions of the calculation on a single line.
Valid Input and Error Checking
You should assume that the user provides all requested inputs (via the keyboard) as instructed,
and assume that all integers are positive numbers. Your program is not required to check the
input or behave in any specific way if the above conditions are not met.
Testing Your Program
Testing is a major component in the process of writing software. Often, testing (detecting
errors) and debugging (locating and fixing errors) takes way more effort than writing the code
did in the first place. We’ll talk more about testing as the quarter progresses; in the meantime,
the following table provides some helpful test cases that you can use to see if your program is
working correctly. Try your code out with the given pairs of integers and see if your output
matches the sum, product, and division result.
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First Integer Second Integer Sum Product Division
7 5 12 35 1 remainder 2
5 7 12 35 0 remainder 5
3 3 6 9 1 remainder 0
1 678 679 678 0 remainder 1
8364724 9738 8374462 81455682312 858 remainder 9520
Submission
Double check that your program works according to the specification. Take a look through
the rubric below and make sure you won’t lose points for reasons that could easily be foreseen
and fixed. When you’re finished, submit your program to Canvas as a single .py file named
arithmetic.py. Finally, fill out the A1 Hours quiz with an estimate of the number of hours
you spent on A1 (include both the written and programming portions in your estimate).
Rubric
Canvas questions 16 points
Author, date, and program description given in comments at the top of the file 1 point
Program prompts for user’s name on the first line 4 points
Greeting on second line includes user’s name 4 points
First integer prompt also appears on second line 2 points
Correct sum output on fourth line 2 points
Correct product output on fifth line 2 points
Division question is rephrased, quotient and remainder are printed on sixth line 3 points
Code is commented adequately and variables are appropriately named 2 points
Total 36 points
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3 Optional Challenge Problem
Some assignments will come with an optional challenge problem. In general, these problems
will be worth very small amounts of extra credit: this one is worth one point. Though the
grade payoff is small, you may find them interesting to work on and test your skills in Python
and algorithm development. The skills and knowledge needed to solve these problems are not
intended to go beyond those needed for the base assignment, but less guidance is provided and
more decisions are left up to you. The A1 challenge problem is as follows:
Many online real estate websites have mortgage calculator features1
. These calculators ask
for some information, such as the price of a home, the down payment (amount of the home
price you’d pay up front), and the interest rate, then calculate the amount you’d have to pay
monthly on a loan for the home.
According to NerdWallet2
, the formula used to calculate the monthly payment based on
these inputs is as follows:
M = (P − D)
r(1 + r)
N
(1 + r)N − 1
Where:
M = The monthly payment
P = The price of the home
D = The down payment amount
N = The number of months over which the loan will be paid off
r = R/12, the monthly interest rate, which is the yearly rate divided by 12
Write a program that asks the user to enter P, D, N, and R, then outputs the monthly
payment amount M. Notice that you will prompt the user for R, the annual interest rate, but
the formula uses r, the monthly interest rate.
3.1 Submission
Upload your submission to Canvas in a file called challenge.py.
1See https://www.zillow.com/mortgage-calculator/ for an example
2Go to https://www.nerdwallet.com/mortgages/mortgage-calculator/calculate-mortgage-payment and click
“How to calculate your mortgage payment” for the source of the formula
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