Numbers 110-120 & Subtraction Facts Basic 1 Mathematics Lesson Note

Subject: Mathematics
Class: Primary 1
Topic: Numbers 110-120 & Subtraction Facts
Duration: 35 minutes

Learning Objectives

By the end of this lesson, pupils should be able to:

• Count and identify numbers from 110 to 120
• Subtract two 1-digit numbers within 20
• Subtract 1-digit numbers from 2-digit numbers within 20

1. COUNTING SKILL: Numbers 110-120

Let’s Learn 110 to 120: 

110 – ONE HUNDRED AND TEN 

111 – ONE HUNDRED AND ELEVEN 

112 – ONE HUNDRED AND TWELVE 

113 – ONE HUNDRED AND THIRTEEN 

114 – ONE HUNDRED AND FOURTEEN 

115 – ONE HUNDRED AND FIFTEEN 

116 – ONE HUNDRED AND SIXTEEN 

117 – ONE HUNDRED AND SEVENTEEN 

118 – ONE HUNDRED AND EIGHTEEN 

119 – ONE HUNDRED AND NINETEEN 

120 – ONE HUNDRED AND TWENTY

Exercise 1: Count from 110 to 120: 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120

Exercise 2: Fill in the missing numbers:

1. 110, 111, ___, 113, ___
2. 115, ___, 117, ___, 119
3. 113, 114, ___, 116, ___

Exercise 3: What comes next?

1. 109, 110, ___
2. 115, 116, ___
3. 118, 119, ___
4. 112, 113, ___

Exercise 4: Complete the sequences:

1. 108, 109, 110, ___, ___, ___
2. 116, 117, ___, ___, 120

2. WRITING NUMBERS 110-120

Practice Writing Numbers 110-120:

Exercise 5: Trace these numbers: 110 110 110 111 111 111 112 112 112 113 113 113 114 114 114 115 115 115

Exercise 6: Trace these numbers: 116 116 116 117 117 117 118 118 118 119 119 119 120 120 120

Exercise 7: Write these numbers:

1. One hundred and twelve: ___
2. One hundred and sixteen: ___
3. One hundred and twenty: ___
4. One hundred and fourteen: ___

3. SUBTRACTION: Two 1-Digit Numbers Within 20

Subtraction with Larger Numbers: When subtracting, we take away to find what is left.

Examples:

• 9 – 2 = 7
• 8 – 5 = 3
• 7 – 4 = 3
• 9 – 6 = 3

Exercise 8: Subtract these numbers:

1. 9 – 3 = ___
2. 8 – 2 = ___
3. 7 – 5 = ___
4. 9 – 4 = ___
5. 8 – 6 = ___

Exercise 9: Find what is left:

1. 🍎🍎🍎🍎🍎🍎🍎🍎🍎 – 🍎🍎🍎 = ___
2. ⭐⭐⭐⭐⭐⭐⭐⭐ – ⭐⭐⭐⭐⭐ = ___

Exercise 10: Complete the subtraction:

1. 9 – 7 = ___
2. 8 – 3 = ___
3. 9 – 1 = ___
4. 7 – 2 = ___

4. SUBTRACTION: 1-Digit from 2-Digit Numbers Within 20

Subtracting from Teen Numbers: When we subtract from numbers like 11, 12, 13… 20, we follow the same rule.

Examples:

• 15 – 3 = 12
• 18 – 5 = 13
• 20 – 7 = 13
• 16 – 4 = 12

Exercise 11: Subtract from teen numbers:

1. 12 – 2 = ___
2. 15 – 3 = ___
3. 18 – 6 = ___
4. 20 – 5 = ___
5. 17 – 4 = ___

Exercise 12: Find the difference:

1. 14 – 3 = ___
2. 19 – 7 = ___
3. 16 – 5 = ___
4. 13 – 2 = ___

Exercise 13: Complete these subtractions:

1. 11 – 1 = ___
2. 20 – 10 = ___
3. 18 – 8 = ___
4. 15 – 5 = ___

Exercise 14: Take away from these numbers:

1. 🏀🏀🏀🏀🏀🏀🏀🏀🏀🏀🏀🏀🏀🏀🏀 – 🏀🏀🏀🏀🏀 = ___
2. 📚📚📚📚📚📚📚📚📚📚📚📚📚📚📚📚📚 – 📚📚📚📚📚📚📚 = ___

5. SUBTRACTION WORD PROBLEMS

Real-Life Subtraction:

Exercise 15: Solve these problems:

1. Tom had 16 marbles. He lost 4 marbles. How many marbles does he have left? 16 – 4 = ___
2. There were 20 birds in the tree. 8 birds flew away. How many birds are left? 20 – 8 = ___
3. Mary had 14 sweets. She gave away 6 sweets. How many sweets are left? 14 – 6 = ___
4. There were 19 books on the shelf. 5 books were taken away. How many books are left? 19 – 5 = ___

Exercise 16: Complete the story problems:

1. Sarah had ___ apples. She ate 3 apples. She has 12 apples left. ___ – 3 = 12
2. There were 18 cars in the parking lot. ___ cars drove away. 11 cars are left. 18 – ___ = 11

Exercise 17: Match the subtraction to the answer:

• 17 – 5 → 9
• 20 – 6 → 12
• 15 – 6 → 14
• 19 – 8 → 11

Exercise 18: True or False:

1. 16 – 4 = 12 ___
2. 18 – 9 = 8 ___
3. 20 – 5 = 15 ___
4. 14 – 6 = 8 ___

Homework

1. Practice counting from 110 to 120 and back
2. Write numbers 110-120 three times each
3. Practice subtraction problems within 20
4. Create 3 subtraction word problems using objects at home
5. Practice subtracting 1-digit numbers from teen numbers

Teacher: Use physical objects to demonstrate subtraction by taking away items from groups