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 Question from Adi, a student: Hi! Can you help me with a nagging problem, I searched a lot over the web and couldn't find it. I saw this site I gave it a try and I found it to my liking. I am confused how to subtract bases from other bases: 567 (in base 8) - 456 (in base 8) ______________ ????????? How do you do this? I do know how to carry and subtract with different bases. Can you please help me? Thanks, Adi

You don't need to carry or borrow to do this subtraction. 7-6=1, 6-5=1 and 5-4=1 and hence

5678 - 4568 = 1118.

You can verify by converting to base ten.

$567_8 = 5\times 8^2 + 6\times 8 + 7 = 375.$

Convert 4568 and 1118 to base ten and check that the difference is correct.

Write back if you need more assistance,
Penny

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