Grade 4 Mathematics Numbers – Whole Numbers Notes

What are whole numbers?

Whole numbers are the numbers: 0, 1, 2, 3, 4, 5, ...
They are used for counting and telling how many. Whole numbers do not include fractions, decimals or negative numbers.

Examples: 0, 7, 25, 314, 1000

Everyday examples (Kenyan context):

• Number of pupils in a class: 32
• Number of matatus on a route (counted): 5
• Kenya has 47 counties — that is a whole number
• Shillings in a coin example: KSh 20 (whole number of shillings)

Place value (reading whole numbers):

Each digit has a place. From right to left: units, tens, hundreds, thousands...

Number line (see whole numbers on a line):

How whole numbers behave:

• Addition: whole + whole = whole (e.g. 4 + 3 = 7)
• Multiplication: whole × whole = whole (e.g. 5 × 6 = 30)
• Subtraction: whole − whole may be whole if result ≥ 0 (e.g. 8 − 3 = 5), but 3 − 8 is not a whole number (it is negative)
• Division: sometimes gives whole number (6 ÷ 3 = 2), sometimes not (5 ÷ 2 = 2.5)

Try these exercises

1. Write five whole numbers between 10 and 20.
2. Which of these are whole numbers? 7, 0, 1.5, −2, 12
3. Place these whole numbers in order from smallest to largest: 34, 9, 50, 12.
4. Fill the blank with a whole number: 15 + ___ = 20
5. A shop has 18 mangoes. If the seller packs them in groups of 6, how many full groups are there?
6. Kenya has 47 counties. Is 47 a whole number? (Yes or No)

Quick tips:

• Remember: whole numbers include zero.
• Decimals like 2.0 are not usually written as whole numbers in class — we write 2 instead.
• If you see a negative sign (−), it is not a whole number.

Teacher note: Use objects (stones, beans, coins) to show whole numbers when teaching. For local context, count things from the classroom or around the compound.