Definition:
Adding decimals,
Write the decimals so that the decimal points line up vertically.
Add as with whole numbers.
Place the decimal point in the sum so that it lines up vertically with the decimal points in the problem.
Subtracting decimals,
Write the decimals so that the decimal points line up vertically.
Subtract as with whole numbers.
Place the decimal point in the difference so that it lines up vertically with the decimal points in the problem.
Calculation:
\(\displaystyle{0.064}-{10.2}\)
The above expression can be written as \(\displaystyle-{10.2}+{0.064}\)
10.2 has 2 whole value.
0.064 has 1 whole value.
So, add 0 to 0.0064 at the front.
The number becomes 00.064
0.064 has 3 decimal places
10.2 has 1 decimal places
So, add 0s to 10.2 at the end.
The number becomes 10.200
Based on the definition,
\(\displaystyle-{10.200}+{00.064}=-{10.136}\)
Answer:
\(\displaystyle{0.064}-{10.2}=-{10.136}\)