Decimal Addition and Subtraction Practice Problems

First let's fill in the zeros in the empty spaces as follows:

$21.52\\+03.40\\$Note that the decimal points are written one below the other.

Therefore, the positions of the decimal points correspond and thus the exercise is written in the correct form.

First let's fill the zeros in the empty space as follows:

$006.310\\+216.222\\\$

Here We should note that the decimal points are written one below the other.

Therefore, the exercise is written in the appropriate form.

Let's solve the subtraction problem step by step:

• Step 1: Align the decimal numbers. The subtraction is $1.8 - 0.9$. Both numbers have their decimal points aligned.
• Step 2: Subtract the numbers starting from the tenths place: $8$ (in $1.8$) minus $9$ (in $0.9$). This requires borrowing.
• Step 3: Regroup, take $1$ from the units place of $1.8$, which then becomes $0.8 + 10$ (or $10$ tenths), thus $18$ tenths. Subtract $9$ tenths from $18$ tenths, resulting in $9$ tenths.
• Step 4: The units digit of $1.8$ now, after borrowing, is $0$. There is nothing left to subtract, so the remaining digit in the unit place remains $0$.
• Step 5: Therefore, the answer obtained is $0.9$.

Thus, the solution to the problem is $\mathbf{0.9}$.

Note that the decimal points are not written one below the other. They do not correspond.

Therefore, the exercise is not written correctly.

Note that the decimal points are not written one below the other. They do not correspond.

Therefore, the exercise is not written correctly.