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}
]