A decimal point has a place.

Add like units together. When ten tenths collect, exchange them for one whole—without changing the value.

First course skill · preview

0 / 3independent first-try streak

0 / 3application checks passed

Preview progress saves in this browser only. No account records are changed.

Where does this matter?

Adding lengths of fabric, lap times or ingredient masses requires matching units. A tenth of a metre is the same size wherever it appears in a written number. Aligning decimal points is how the written method keeps those units together.

Next skill: subtracting decimals →All Arithmetic skills

This is one skill in Arithmetic, not the whole subtopic. Subtraction is available next. Multiplication, division, fraction arithmetic and order of operations are planned. Original Cambridge-style questions; preview evidence is not a mastery certificate.