Decimals · Grade 6
In Grade 6 you learn: multiplying and dividing decimals.
Decimals carry place value past the decimal point into tenths, hundredths and thousandths. Money, measurements and calculator answers are all written as decimals, so reading, ordering and calculating with them is an everyday skill.
Key facts
- After the point come tenths, hundredths, thousandths. In 3.47 the 4 is worth 0.4 and the 7 is worth 0.07.
- To compare decimals, line up the points and compare digit by digit (fill gaps with zeros): 0.5 > 0.45.
- To add or subtract, line up the decimal points.
- × 10 moves the digits 1 place left, × 100 moves them 2 places and × 1,000 moves them 3. ÷ moves them right.
- To multiply decimals, multiply as whole numbers. The answer has as many decimal places as the question.
- To divide by a decimal, multiply both numbers by 10, 100, … until you are dividing by a whole number.
Worked examples
Example 1
Put these in order, smallest first: 0.6, 0.56, 0.065, 0.605
Answer: 0.065, 0.56, 0.6, 0.605
Example 2
Work out 12 − 4.37.
Answer: 7.63
Example 3
Work out 0.3 × 0.04.
Answer: 0.012
Example 4
A 2.4 m plank is cut into pieces 0.15 m long. How many pieces are there?
Answer: 16