Because the number is the square of its units digit, it must be the square of a number between 1 and 9. Look at the squares of the first nine numbers.
The square of 1 is 1.
The square of 2 is 4.
The square of 3 is 9.
The square of 4 is 16.
The square of 5 is 25.
The square of 6 is 36.
The square of 7 is 49.
The square of 8 is 64.
The square of 9 is 81.
Of these numbers, 1, 25, and 36 are squares of their units digit.
17
This is two problems. Surface area is measured in square units. The formulas for the area of different figures vary with the figures. The area of a regular four-sided figure is the length times the width. To round a number to a particular digit, look at the digit immediately to the right of your target, in this case, tenths of square units. If that digit is 4 or lower, zero it and everything to the right of it out. If that digit is 5 or higher, increase the target digit by one and zero everything to the right of it out. If your target digit is a 9, increasing it will turn it to zero and increase the digit to the left of it by one.
Any two digit number in which: (a) the units digit is not 0, and (b) the two digits are different will form a new 2-digit number when the digits are interchanged.
The nth triangular number is given by ½ × n × (n+1)→ the 5857th triangular number is ½ × 5857 × 5858 = 17,155,153, so its units digit is a 3.------------------------------------------------------------Alternatively,If you look at the units digits of the first 20 triangular numbers they are {1, 3, 6, 0, 5, 1, 8, 6, 5, 5, 6, 8, 1, 5, 0, 6, 3, 1, 0, 0}At this stage, as we are only concerned with the units digit, as we now have a 0 for the units digit, when 21 is added it is the same as adding 1 to 0 to give a 1, for the 22nd triangular number, we are adding 2 to the 1 to give 3, and so on - the sequence of 20 digits is repeating.To find the units digit of the nth triangular number, find the remainder of n divided by 20 and its units digit will be that digit in the sequence (if the remainder is 0, use the 20th number). To find the remainder when divided by 20 is very simple by looking at only the tens digit and the units digit:If the tens digit is even (ie one of {0, 2, 4, 6, 8}), the remainder is the units digitIf the tens digit is odd (ie one of {1, 3, 5, 7, 9}), the remainder is the units digit + 10.5857 ÷ 20 = ... remainder 17; the 17th digit of the above sequence is a 3, so the units digit of the 5857th triangular number is a 3.This trick can be used for much larger triangular numbers which calculators cannot calculate exactly using the above formula. eg the units digit of the 1234567890123456789th triangular number is... 1234567890123456789 ÷ 20 = .... remainder 9, so this triangular number's units digit is the 9th digit of the above sequence which is a 5.
961
The number in the units digit of the number 921 is 9.
The units digit of a whole number is always the rightmost digit.
The digit in the units column of the number 7157 is 7.
The units digit of a two digit number exceeds twice the tens digit by 1. Find the number if the sum of its digits is 10.
8 : the units digit is the first digit to the left of the decimal point if you had to write one in.
"If the units digit and the hundreds digit of the number 513 were reversed..." 315 'find the sum of the original number and the new number." 513+315=828
84
When the tens digit is even and the units digit is 0, 4 or 8 or the tens digit is odd and the units digit is 2 or 6.
16, which is the square of 4, is a two digit even number.
Oh, dude, okay, so when you raise 2013 to the power of 2013, you're basically asking what the units digit of that massive number is. Well, lucky for you, you don't need to calculate the whole thing because the units digit of a number repeats in a pattern. So, the units digit of 2013 to the power of 2013 is 7. Cool, right?
24
It is the digit 7 that is in the ones or units place