fractionsDecimals · Year 6 · AC9M6N04
Adding decimals in columns
When you add decimals, line up the decimal points, not the last digits. Write the numbers one above the other so the points sit in a straight line, then add each column from the right just like whole numbers. Bring the decimal point straight down into the answer. It helps to pad with zeros at the end so both numbers have the same length: 2.5 becomes 2.50, then 2.50 + 0.25 = 2.75. The extra zero always goes at the end, never straight after the point.
Sample questions
3.3 + 0.52 = ? (Line up the decimal points.)
- Line up the points: write 3.30 above 0.52.
- Add each column from the right to get 3.82.
- So 3.3 + 0.52 = 3.82.
Answer: 3.82
4.2 + 0.12 = ? (Line up the decimal points.)
- Line up the points: write 4.20 above 0.12.
- Add each column from the right to get 4.32.
- So 4.2 + 0.12 = 4.32.
Answer: 4.32
1.8 + 0.42 = ? (Line up the decimal points.)
- Line up the points: write 1.80 above 0.42.
- Add each column from the right to get 2.22.
- So 1.8 + 0.42 = 2.22.
Answer: 2.22