Whole Numbers Notes, Quizzes & Revision

Notes: Whole Numbers

Subject: subject_replace  |  Topic: topic_name_replace  |  Target age: age_replace (Kenyan context)

1. What are whole numbers?

Whole numbers are the numbers we use for counting and ordering that include 0 and the positive integers: 0, 1, 2, 3, ... . They do not include fractions or negative numbers.

2. Examples from everyday Kenyan life

• Number of students in a class: 35
• Number of matatus on a route: 12
• Kenyan shillings in whole notes: KSh 50, KSh 100 (whole amounts like 100 are whole numbers)
• 0 ugali left after cooking means zero whole portions remain

3. Place value (reading and writing whole numbers)

Each digit in a whole number has a place value. Example: 4, 275 reads as "four thousand two hundred seventy-five".

4. Comparing and Ordering

Use > (greater than), < (less than) or = (equal to).

Examples: 48 > 32, 100 > 99, 15 < 20, 40 = 40

5. Number line (visual)

A number line helps show order and distance between whole numbers:

6. Operations with whole numbers

- Addition: joining groups. Example: 27 + 15 = 42.
- Subtraction: taking away. Example: 50 - 18 = 32.
- Multiplication: repeated addition. Example: 4 × 6 = 24.
- Division: sharing into equal parts. Example: 24 ÷ 6 = 4.

Properties of whole numbers

• Commutative (addition and multiplication): 3 + 5 = 5 + 3; 2 × 7 = 7 × 2
• Associative: (2 + 3) + 4 = 2 + (3 + 4)
• Distributive: 3 × (4 + 2) = 3×4 + 3×2
• Zero is the additive identity: 0 + n = n

7. Word problems (Kenyan context)

1. Mary sells 15 mangoes each morning. In 4 mornings how many mangoes does she sell? (15 × 4 = 60)
2. A class has 42 pupils. They form 6 equal groups for a game. How many pupils in each group? (42 ÷ 6 = 7)
3. Bus ticket costs KSh 120. For 5 people, how much in total? (120 × 5 = KSh 600)
4. There are 90 books to be shared equally among 9 schools. How many books per school? (90 ÷ 9 = 10)

8. Practice exercises

Write answers and check below.

1. Write the following in words: 3,406
2. Which is greater: 7,892 or 7,829?
3. Compute: 268 + 137
4. Compute: 500 − 275
5. Compute: 23 × 6
6. Compute: 84 ÷ 7
7. Ken buys 3 pens at KSh 45 each. How much did he pay?
8. There are 120 pupils. They sit 5 pupils on each bench. How many benches are needed?

Answers

1. Three thousand four hundred six
2. 7,892 is greater than 7,829
3. 268 + 137 = 405
4. 500 − 275 = 225
5. 23 × 6 = 138
6. 84 ÷ 7 = 12
7. 3 × 45 = KSh 135
8. 120 ÷ 5 = 24 benches

9. Tips for learners (age_replace)

• Use real objects (stones, pens, coins) to count and practice addition or subtraction.
• Draw number lines for subtraction and for seeing how numbers increase when adding.
• Write numbers in groups of three (commas) to read large numbers easily — e.g., 12,345.
• Relate problems to things you know in Kenya: money (KSh), people, buses, school items.

End of notes on Whole Numbers — topic: topic_name_replace, subject: subject_replace, for age: age_replace.