Let's consider a number 25.83 to be added by 3.2. Now in the 25.83, 2 is tens place and 5 at one's place. 8 is at the tenths place and 3 is at the hundredths place. In 3.2, 3 is one's place and 2 is at tenth's place. Now while adding we need to make sure we add similar things. Like tens with tens, ones with ones & hundredths with hundredths. (idk what this word is) to keep similar places together to get added, we line up we line up decimals first as all places are with (idk) to the decimal (same word as the one above i think) addition will be.
25.83+3.2=29.03 ans
I think that's what it says. Hopefully this helps, I'll try to figure out what those other words are it might take a second. I'll edit or comment if I figure it out.