Addition of Numbers – Basic 3 Mathematics Lesson Note (First Term)

Counting skill: numbers 701-720, 401-720, 1-720

Counting from 701 to 720: 701, 702, 703, 704, 705, 706, 707, 708, 709, 710, 711, 712, 713, 714, 715, 716, 717, 718, 719, 720

Counting by 100s from 1-720: 100, 200, 300, 400, 500, 600, 700

Counting by 10s from 700-720: 700, 710, 720

Practice counting:

• From 705 to 715: _______
• From 712 to 720: _______
• Backwards from 720 to 710: _______

Number patterns:

• 701, 703, 705, _____, _____
• 720, 715, 710, _____, _____
• What comes before 710? _____
• What comes after 719? _____

B. writing skill: writing of the numbers

Write in words:

• 701 = Seven hundred and one
• 705 = Seven hundred and five
• 710 = Seven hundred and ten
• 715 = Seven hundred and fifteen
• 720 = Seven hundred and twenty

Write in figures:

• Seven hundred and three = _______
• Seven hundred and eight = _______
• Seven hundred and twelve = _______
• Seven hundred and seventeen = _______
• Seven hundred and nineteen = _______

Practice:

• 707 = _______
• 714 = _______
• Seven hundred and six = _______
• Seven hundred and eighteen = _______

C. addition of numbers

Review of addition rules:

• Add units to units
• Add tens to tens
• Add hundreds to hundreds
• Carry over when sum is 10 or more

Simple addition:

 234      567

+ 125    + 142

—–    —–

  359      709

Addition crossing 700:

 678

+ 145

—–

  823

Practice:

1. 456 + 123 = _____
2. 567 + 152 = _____
3. 678 + 45 = _____
4. 345 + 267 = _____

D. addition using partial sum method

What is partial sum method? Breaking numbers into parts (hundreds, tens, units) and adding each part separately.

Example: 234 + 156

Step 1: Break into parts

• 234 = 200 + 30 + 4
• 156 = 100 + 50 + 6

Step 2: Add each part

• Hundreds: 200 + 100 = 300
• Tens: 30 + 50 = 80
• Units: 4 + 6 = 10

Step 3: Add the partial sums 300 + 80 + 10 = 390

Another example: 467 + 258

• 467 = 400 + 60 + 7
• 258 = 200 + 50 + 8
• Hundreds: 400 + 200 = 600
• Tens: 60 + 50 = 110
• Units: 7 + 8 = 15
• Total: 600 + 110 + 15 = 725

Practice partial sum method:

1. 345 + 234:
   1. 345 = _____ + _____ + _____
   2. 234 = _____ + _____ + _____
   3. Answer: _____
2. 456 + 267:
   1. Hundreds: _____ + _____ = _____
   2. Tens: _____ + _____ = _____
   3. Units: _____ + _____ = _____
   4. Total: _____

E. quantitative reasoning

Word problems:

1. A library has 456 story books and 267 textbooks. How many books are there altogether?
2. On Monday, 234 pupils came to school. On Tuesday, 289 pupils came. What is the total number of pupils for both days?
3. A farmer sold 345 oranges in the morning and 278 in the evening. How many oranges did he sell in total?

Number sentences:

1. _____ + 234 = 567
2. 345 + _____ = 678
3. 456 + 267 = _____

Estimation using partial sums:

1. 234 + 189 ≈ 200 + 30 + 4 + 100 + 80 + 9 = _____
2. 456 + 278 ≈ 400 + 50 + 6 + 200 + 70 + 8 = _____

Pattern recognition:

1. 100 + 200 = 300, 150 + 250 = _____, 200 + 300 = _____
2. 234 + 123 = 357, 235 + 124 = _____, 236 + 125 = _____

CLASS EXERCISES

1. Count from 708 to 718:
2. Write in words:
   1. 703 = _______
   2. 716 = _______
   3. 720 = _______
3. Write in figures:
   1. Seven hundred and four = _______
   2. Seven hundred and eleven = _______
4. Add using column method:
   1. 234 + 167 = _____
   2. 456 + 278 = _____
5. Use partial sum method:
   1. 345 + 256: Hundreds: _____ + _____ = _____ Tens: _____ + _____ = _____ Units: _____ + _____ = _____ Total: _____
6. Word problems:
   1. A school has 345 pupils in the morning and 278 in the afternoon. How many pupils are there in total?
   2. Tolu collected 234 bottle caps on Monday and 189 on Tuesday. How many bottle caps did he collect altogether?
7. Fill in the missing numbers:
   1. 234 + _____ = 567
   2. _____ + 178 = 456
8. Break these numbers into hundreds, tens, and units:
   1. 567 = _____ + _____ + _____
   2. 389 = _____ + _____ + _____
9. Estimate using rounding:
   1. 234 + 189 ≈ _____ + _____ = _____
10. Solve using partial sum method:
    1. 456 + 267 = _____
    2. 345 + 289 = _____