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n = (28)^3
which is greater:
the units digit of n
OR
4?
How does one go about *computing* the units digit of n?
which is greater:
the units digit of n
OR
4?
How does one go about *computing* the units digit of n?
cepheid said:That's the *general strategy*, then? Factor the number.
robert Ihnot said:Werg22: There's an even simpler way: the unit digit in 28 is 8, 8^3 = 8*64 - > this ends with a 2. This said, 28^3 ends with a 2.
robert Ihnot said:We look at this modulo 10, 28==8. On the other hand we can also use 8==-2 Mod 10, so all we have to do is look at (-2)^3=-8==2 Mod 10, and we are done!
robert Ihnot said:This way helps because suppose the problem was (7598)^10. That matter reduces to (-2)^10 = 64 == 4 Mod 10.
matt grime said:That last sentence indicates you don't understand what 'mod 10' means at all.
cepheid said:3. (-2)^10 = 64
Now THIS is the statement of robert Inhot that I did not understand...it does not make sense to me in ANY form of arithmetic.
d_leet said:I think that was a mistake becaue you would have (-2)^10=1024==4(mod 10)
cepheid said:Great! Now that that has been established, can anyone help me out with my question? (post 10).
The units digit is the rightmost digit in any number and represents its value in the ones place. It is important because it can affect the overall value and properties of a number, such as its divisibility and place in a sequence.
To determine if the units digit of a number is greater than 4, you simply look at the rightmost digit. If it is 5, 6, 7, 8, or 9, then the units digit is greater than 4. If it is 0, 1, 2, 3, or 4, then the units digit is less than or equal to 4.
No, the units digit of a number cannot be negative. The units digit represents the value in the ones place, which can only be a positive number. Negative numbers have a units digit of 0.
The probability of the units digit being greater than 4 in a randomly generated number is 5 out of 10, or 50%. This is because there are 5 numbers (5, 6, 7, 8, 9) that are greater than 4, and there are a total of 10 possible digits (0-9).
The units digit can help determine divisibility by certain numbers because it is the last digit in a number and can give information about the overall value. For example, if the units digit is 0 or 5, the number is divisible by 5. If the units digit is even (0, 2, 4, 6, 8), the number is divisible by 2. This can be helpful in quickly determining the divisibility of a number without having to perform the full division calculation.