Addition and Subtraction
Addition is the process of combining two or more numbers to find their total.
Subtraction is the process of finding the difference between two numbers.
Example 1.3
Solve the following:
- (a) 25 + 7,890 + 56,843
- (b) 906,874,304 − 67,345,907
Solution
(a) Addition (with Carry)
\[
\begin{array}{r}
\color{#1565c0}{1} \\[2pt]
\ 25 \\
+ 7\,890 \\
+56\,843 \\
\hline
64\,758
\end{array}
\]
- Add the ones first, then move left.
- When a column exceeds 9, carry to the next place value.
(b) Subtraction (with Borrowing)
\[
\begin{array}{r}
906\,874\,304 \\
-67\,345\,907 \\
\hline
839\,528\,397
\end{array}
\]
- If the top digit is smaller, borrow from the next place value.
- Subtract carefully column by column.
Watch and Learn 🎥
This video explains addition and subtraction with carrying and borrowing clearly.
NOTE
- Addition is commutative: \(a + b = b + a\). The order of numbers does not matter.
- Subtraction order matters: \(a - b \neq b - a\).
Addition and Subtraction Exercise
Fill in your answers and click "Check Answer". Then click "Show Working" to see the step-by-step solution.
\[
\begin{array}{r}
45\,302 \\
+ 46\,783 \\
\hline
92\,085
\end{array}
\]
\[
\begin{array}{r}
345\,678 \\
+ 90\,458 \\
\hline
436\,136
\end{array}
\]
\[
\begin{array}{r}
7\,567 \\
+ 87\,456 \\
\hline
95\,023
\end{array}
\]
\[
\begin{array}{r}
34\,735 \\
+ 12\,378 \\
\hline
47\,113
\end{array}
\]
\[
\begin{array}{r}
9\,253 \\
+ 6\,106 \\
\hline
15\,359
\end{array}
\]
\[
\begin{array}{r}
20\,387 \\
+ 11\,032 \\
\hline
31\,419
\end{array}
\]
\[
\begin{array}{r}
879\,234 \\
- 76\,903 \\
\hline
802\,331
\end{array}
\]
\[
\begin{array}{r}
803\,782 \\
- 66\,783 \\
\hline
736\,999
\end{array}
\]
\[
\begin{array}{r}
564\,128 \\
- 555\,729 \\
\hline
8\,399
\end{array}
\]
\[
\begin{array}{r}
785\,093 \\
- 567\,387 \\
\hline
217\,706
\end{array}
\]
\[
\begin{array}{r}
900\,075 \\
- 878\,273 \\
\hline
21\,802
\end{array}
\]
\[
\begin{array}{r}
123\,678 \\
- 99\,878 \\
\hline
23\,800
\end{array}
\]