Halfway Between 21 and 255

When you ask "What number is halfway between 21 and 255?" we assume you mean the number in the exact middle of the two numbers on a number line, as illustrated below, where X=21 and Y=255.

Halfway Between Line

To find the number halfway between 21 and 255, we use the following formula:

(X + Y)/2 = Halfway Between

When we enter 21 and 255 into our formula, we get:

(21 + 255)/2 = 138

Thus, the number halfway between 21 and 255 is 138.

To check that our answer is correct, we subtract 21 from 138 and subtract 138 from 255 and compare the two numbers:

138 - 21 = 117
255 - 138 = 117

As you can see, the halfway number is 117 higher than 21 and 117 lower than 255. Therefore, our halfway between answer of 138 above is correct.

Halfway Between
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Halfway Between 21 and 256
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