Mixed Operations (Addition And Subtraction) Basic 2 Mathematics Lesson Note

Learning Objectives

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

• Count and identify numbers from 1-450
• Write numbers 430-450 and 1-450 in numerals and words
• Add numbers from 1-500
• Subtract numbers from 1-500
• Solve problems using hundreds, tens, and units
• Solve real-life problems with mixed operations
• Review skip counting in 2s, 3s, 5s, and 10s

Lesson Content

Day 1: Counting to 450 and Skip Counting Review

New Number Range:

• Practice counting from 1-450
• Focus on numbers 430-450: 430, 431, 432… 450
• Master reading and writing these numbers

Skip Counting Review:

• Count in 2s: 2, 4, 6, 8… up to 100
• Count in 3s: 3, 6, 9, 12… up to 60
• Count in 5s: 5, 10, 15, 20… up to 100
• Count in 10s: 10, 20, 30, 40… up to 100

Day 2-3: Mixed Operations Practice

What are Mixed Operations? Mixed operations means using both addition (+) and subtraction (-) in our math work.

When to Add:

• When we put things together
• When we want the total
• When something is given or added

When to Subtract:

• When we take things away
• When we want what’s left
• When something is removed or lost

Example Problem: “Tom has 45 marbles. His friend gives him 23 more marbles. Then Tom gives 15 marbles to his sister. How many marbles does Tom have now?”

• Step 1: 45 + 23 = 68 marbles
• Step 2: 68 – 15 = 53 marbles left

Day 4: Using Place Value in Operations

Understanding Hundreds, Tens, and Units: When adding or subtracting large numbers, we work with:

• Hundreds column (H)
• Tens column (T)
• Units column (U)

Example with Place Value:

  H  T  U

   2  3  5  = 235

+  1  4  2  = 142

———–

   3  7  7  = 377

Day 5: Real-Life Mixed Problems

Complex Real-Life Scenarios: These problems need more than one step to solve:

Shopping Example: “Mom has 150 naira. She buys bread for 45 naira and milk for 32 naira. How much money does she have left?”

• Step 1: Add expenses: 45 + 32 = 77 naira spent
• Step 2: Subtract from total: 150 – 77 = 73 naira left

Examples in Class

Mixed Operation Examples:

Example 1: “A school has 125 boys and 134 girls. If 89 pupils go home early, how many pupils are still in school?”

• Step 1: Total pupils = 125 + 134 = 259 pupils
• Step 2: Pupils remaining = 259 – 89 = 170 pupils

Example 2: “A farmer has 87 chickens. He buys 25 more chickens, then sells 38 chickens. How many chickens does he have now?”

• Step 1: 87 + 25 = 112 chickens
• Step 2: 112 – 38 = 74 chickens

Place Value Example:

Adding 245 + 132:

H T U

2 4 5

1 3 2

—–

3 7 7

• Units: 5 + 2 = 7
• Tens: 4 + 3 = 7
• Hundreds: 2 + 1 = 3

Exercises

Exercise 1: Number Practice

Write these numbers:

1. Four hundred and thirty-five = ___
2. Four hundred and forty-seven = ___
3. 439 in words = ___
4. 448 in words = ___

Exercise 2: Skip Counting Review

Fill in the missing numbers:

1. 2, 4, ___, 8, ___, 12
2. 5, 10, ___, 20, ___, 30
3. 10, 20, ___, 40, ___, 60
4. 3, 6, ___, 12, ___, 18

Exercise 3: Mixed Operations

Solve these step by step:

1. 45 + 32 – 26 = ___
2. 67 – 24 + 18 = ___
3. 58 + 27 – 35 = ___
4. 89 – 45 + 23 = ___

Exercise 4: Place Value Addition

Solve using place value:

1. 234 2. 156 3. 278

• 125 + 132 + 121

Exercise 5: Place Value Subtraction

Solve using place value:

1. 367 2. 289 3. 456

• 142 – 156 – 234

Exercise 6: Two-Step Word Problems

Solve these mixed operation problems:

1. A shop has 156 apples and 89 oranges. If 67 fruits are sold, how many fruits are left? 
2. Mary has 75 stickers. Her friend gives her 28 more stickers. Then Mary gives 35 stickers to her brother. How many stickers does Mary have now? 
3. A school has 234 pupils. 45 new pupils join the school. Later, 67 pupils leave. How many pupils are in the school now? 

Exercise 7: Real-Life Problems

1. Dad has 200 naira. He buys fuel for 85 naira and bread for 23 naira. How much money does he have left? 
2. A library has 345 books. They buy 78 new books, then lend out 156 books. How many books are left in the library? 

Fun Activities

• Operation Detective: Decide whether to add or subtract in word problems
• Two-Step Challenges: Create complex problems for classmates
• Place Value Games: Use base-10 blocks for operations

Homework

• Practice 5 mixed operation problems daily
• Create 2 two-step word problems using situations at home
• Review all skip counting patterns
• Help parents with calculations involving money

Assessment

• Can the child count to 450 accurately?
• Do they know when to add and when to subtract in word problems?
• Can they solve two-step problems correctly?
• Can they use place value understanding in operations?
• Can they apply mixed operations to real-life situations?
• Do they remember all skip counting patterns?