Which of the numbers below does not belong with the others? A) two-fourths, B) 50 percent, C) fifty tenths, D) one-half, or E) fifty
Most of our options are in fraction form. One of them is written as a percent. So it’s up to us: we can either change all of the numbers to be a reduced fraction,
make them all be percentages, or make them all be decimals. Let’s try two ways. Let’s change them all to decimals. And then we can also try by making them all fractions since most of them are already
in fraction form.
So let’s begin writing them as decimals. So to write a fraction as a decimal, it’s pretty simple: you take the numerator and
divide by the denominator. So two divided by four and we get 0.50.
Now, option B is a percentage. So to go from a percent to a decimal, we drop the percent sign and move the decimal
place two places to the left. So we drop the percent sign. The decimal point is here. So moving two places to the left would give us 0.50, if we would put the zero in
front of the decimal place, which is a good idea to do so the decimal place sticks
out a little more.
Option C, it’s a fraction. So 50 divided by 10, that’s five. So this one sticks out. This is probably our answer, but let’s keep going. Option D is one-half. So one divided by two is 0.50. And then E, fifty one-hundredths, 50 divided by 100 is 0.50. So the number that does not belong would be C.
Let’s go ahead and go through and do this as if we’re changing them all to be reduced
fractions. So A was two-fourths. Two-fourths reduces to one-half. 50 percent as a fraction, there’s 100 percent that would be the four. So 50 percent will be 50 out of the 100. And fifty one-hundredths reduces to one-half. And then C, fifty tenths that reduces to five over one, which is different. And then in D, one-half, that does not reduce. It stays one-half. And then fifty one-hundredths reduces to one-half. So again, this would still give us that the number that does not belong would be