Subtraction (Continued)
Subtraction (Continued)
Primary 1 · Mathematics · First Term · Week 10
By the end of this lesson, pupils should be able to:
- Subtract numbers within 10 using objects
- State the result of subtracting zero from a number
- Solve word problems involving subtraction up to 10
- Demonstrate subtraction using real objects
Subtracting Within 10
For bigger numbers, counters make the “taking away” visible. To solve 8 – 3: count out 8 counters, physically remove 3 and set them aside, then count what’s left in the original group — 5. So 8 – 3 = 5. A number line works the same way: start at 8, hop backward 3 spaces, and land on 5.
The Rule for Subtracting Zero
If nothing is taken away, everything stays. Any number minus zero equals that same number — 6 books minus 0 books leaves you with all 6 books: 6 – 0 = 6.
Word Problems Within 10
Identify the starting amount and what’s being taken away. Example: “There are 10 birds on a tree branch. 5 fly away. How many are left?” Start at 10, take away 5: 10 – 5 = 5 birds remain.
Linking Subtraction Back to Addition
Subtraction and addition are opposites, and connecting them strengthens both. If 5 + 4 = 9, then 9 – 4 should equal 5. Try it: place 9 crayons on the desk, take away 4, and count what’s left — 5.
Evaluation
- What is 7 – 3?
- Solve: 9 – 0.
- If you have ₦10 and spend ₦5 on a sweet, how much do you have left?
- What is 8 – 2?
- Solve: 6 – 6.
Assignment
- Solve: 10 – 4 = ?
- Solve: 8 – 2 = ?
- “Tolu had 5 balls. He lost 0 balls. How many does he have now?”