alleryStart learning →When adding or subtracting decimals, what is the first step?
ALine up the decimal points vertically
BRound to the nearest whole number first
CConvert both numbers to fractions
DMultiply both numbers by 100 first
Answer & Solution
Correct answer: A. Line up the decimal points vertically
1. Decimal addition and subtraction follow the same column method as whole numbers.
2. For the columns to line up correctly, the decimal points must be aligned.
3. The first step is to write the numbers vertically so the decimal points line up.
4. Rounding first, converting to fractions, or multiplying by 100 are not part of the standard procedure and would change the numbers before adding or subtracting them.
_Source: OpenStax Prealgebra (CC BY 4.0), Ch 5 "Decimals", section 5.2 Decimal Operations_
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