You have to round it or just keep it the way it is. Another way to do it would be to
Sum is an answer to an addition problem.
0.7 0.5
When the fractional parts, if any, of the two decimal numbers sum to 1.
18.812 and 31.187
This will happen if the fractional parts of the numbers sum to 1.
Its perimeter is the sum of its 4 sides
For example: 0.25+0.75 = 1.0
0.79 4.3
An infinite number, like 1.25 and 0.75
we are not doing your homework for you
yes
Two decimals that meet your criteria are 1.500 and 0.500. Their sum is 2.000, which is exactly 2, and their difference is 1.000, which is close to 1.