🧮 Class 1 Mathematics – Chapter 4: Subtraction
🔹 1. What is Subtraction?
Subtraction means taking away or finding how many are left.
It is the opposite of addition.
👉 Example:
If you have 5 apples 🍎 and you give 2 away,
then you have 3 apples left.
5 − 2 = 3
🔹 2. The Minus (−) and Equal (=) Signs
-
‘−’ (minus sign): used when we subtract.
-
‘=’ (equal sign): shows the result.
👉 Example:
7 − 2 = 5
(read as “Seven minus two equals five.”)
🔹 3. Meaning of Subtraction
| Situation | Example | Result |
|---|---|---|
| Taking away | 6 − 2 = 4 | (Take away 2 from 6) |
| Finding how many left | 8 − 3 = 5 | (3 are taken away, 5 left) |
| Comparing | 7 − 5 = 2 | (7 is 2 more than 5) |
🔹 4. Subtraction Using Pictures
Count and cross out to see how many are left.
Example:
🍎🍎🍎🍎🍎
If we take away 🍎🍎
2 apples → ❌❌
Left = 🍎🍎🍎
5 − 2 = 3
🔹 5. Subtraction on Number Line
Example:
To find 7 − 3,
-
Start at 7
-
Move 3 steps backward
👉 You reach 4
✅ So, 7 − 3 = 4
🔹 6. Subtracting Zero
When you subtract 0, the number stays the same.
👉 5 − 0 = 5
👉 8 − 0 = 8
🔹 7. Subtracting the Same Number
When you subtract the same number, the answer is zero.
👉 6 − 6 = 0
👉 3 − 3 = 0
🔹 8. Subtraction Facts
| Number | Subtract 1 | Result |
|---|---|---|
| 1 | −1 | 0 |
| 2 | −1 | 1 |
| 3 | −1 | 2 |
| 4 | −1 | 3 |
| 5 | −1 | 4 |
| 6 | −1 | 5 |
🔹 9. Subtraction Using Fingers
Show 5 fingers ✋
Fold down 2 fingers.
Count the fingers still up → 3
✅ 5 − 2 = 3
🔹 10. Word Problems (Story Sums)
Example 1:
Rita had 6 balloons. 🎈
2 balloons flew away.
How many balloons are left?
👉 6 − 2 = 4
Example 2:
There were 8 birds on a tree. 🐦
3 flew away.
How many birds are left?
👉 8 − 3 = 5
Example 3:
A box has 10 chocolates. 🍫
Rahul eats 4.
Chocolates left = ?
👉 10 − 4 = 6
🔹 11. Practice Exercise
| No. | Question | Answer |
|---|---|---|
| 1 | 5 − 2 | 3 |
| 2 | 9 − 3 | 6 |
| 3 | 7 − 1 | 6 |
| 4 | 8 − 4 | 4 |
| 5 | 6 − 6 | 0 |
| 6 | 10 − 5 | 5 |
| 7 | 4 − 2 | 2 |
| 8 | 3 − 0 | 3 |
| 9 | 9 − 9 | 0 |
| 10 | 7 − 3 | 4 |
🔹 12. Important Points to Remember
✅ Subtraction means “take away” or “how many left.”
✅ The sign used is “−”.
✅ Subtracting 0 gives the same number.
✅ Subtracting a number from itself gives 0.
✅ We can subtract using fingers, pictures, or a number line.
🧠 Quick Revision
| Concept | Example |
|---|---|
| Taking away | 6 − 2 = 4 |
| Subtracting zero | 5 − 0 = 5 |
| Subtracting same number | 4 − 4 = 0 |
| Word problem | 8 − 3 = 5 birds left |
| Number line | Move backward to subtract |