7.1. To add or subtract fractions, they must be renamed to have a common denominator.
7.2. Decimal fractions arise out of division.
7.3. The “ten for one” and “one for ten” canons apply when adding and subtracting with decimal fractions (one decimal place-fractions).
7.4. Subtraction can produce negative numbers.
7.5. Round whole numbers and decimals, with up to two places, to the nearest whole number, or tenth.
7.6. Carry out column addition and subtraction for whole numbers and decimals.