Python Forum

Howdy. I'm taking a class on Python in college, and I've come across a problem where I don't know what I'm supposed to be trying to do. I understand that I'm supposed to be completing a program, but I can't figure out what to do to complete it, and have no idea what the goal is supposed to be.

**Please don't give me the answer right away. I would really just appreciate some guidance to point me in the right direction.

Here are the instructions:

Times 11: A two-digit number can be easily multiplied by 11 in one's head simply by adding the digits and inserting that sum between the digits. For example, 43 * 11 has the resulting digits of 4, 4+3, and 3, yielding 473. If the sum between the digits is greater than 9, then the 1 is carried to the hundreds place. Complete the below program.

Here is the program/code:

# Complete the following program

num_in_tens = int(input('Enter the tens digit:\n'))
num_in_ones = int(input('Enter the ones digit:\n'))

num_in = num_in_tens*10 + num_in_ones

print('You entered', num_in)
print(num_in, '* 11 is', num_in*11)

num_out_hundreds = num_in_tens
#num_out_tens = ? FINISH
#num_out_ones = ? FINISH

print('An easy mental way to find the answer is:')
print(num_in_tens, ',', num_in_tens, '+', num_in_ones, ',', num_in_ones)

#Build num_out from its digits:
#num_out = ? + ? + ? FINISH

# Note this line will generate an error until the above program is complete.
print(num_out)

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I don't understand what num_out is supposed to be, and I don't understand what "Build num_out from its digits." is supposed to mean.

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I've been trying to figure it out for about two hours, now.
Just a reply in another thread where someone said to show what the OP had already tried, and then they would help. I didn't save anything that I've tried, because I didn't realize that it would be needed, but that does make lots of sense to save it. Sorry I don't have that, but I hope that you can still help me with this. I'll be sure to save my future attempts.

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Just READ a reply in another thread...

I think num_out is supposed to be num_in times 11. Building it with digits means to use the "easy mental way" given by the program, using num_out_hundreds/tens/ones variables.

#Build num_out from its digits:
#num_out = ? + ? + ? FINISH

Why does it give "#num_out = ? + ? + ?" as the format, when it's not the format used to find the number times 11? The format to finding the product of a two-digit number times 11 is "num_tens, num_tens + num_ones, num_ones". This is one of the main things confusing me.

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I also don't understand what num_out_tens and num_out_ones is supposed to be. Am I just supposed to guess what those values are supposed to be?

I'm assuming num_out_tens is the tens digit in the answer, and num_out_ones is the ones digit in the answer.

I tried that, but all that comes out to is 16, which is completely unrelated.

By the way, thank you for your quick responses.

Are you multiplying the tens by ten and hundreds by one hundred?