Free interactive math game: Column Add (Decimals) — Align decimal points. Part of the Long Arithmetic category on MathKite.
Taken from the generator that powers this exercise. A fresh set appears every time the page is opened, and the printable worksheet holds ten of them.
Adding decimals with the written column method.
Write one number above the other with the decimal points stacked vertically, filling ragged ends with zeros. Then add each column from the right, carrying past the point as if it were not there.
Stacking 7.72 above 7.93 and adding column by column gives 15.65, with a carry crossing the point.
Letting the points drift out of line. A slanted stack adds tenths to hundredths, and no amount of careful adding can rescue it.