Number Classification Notes & Questions | Class 4 Reasoning | Drishti OS

Number Classification

Find the number that does not share a property with the others (odd/even, multiples).
Recall even and odd numbers.
Recall multiples of small numbers like 3, 4, 5, 10.

Even numbers end in 0, 2, 4, 6, 8. Odd numbers end in 1, 3, 5, 7, 9.

A multiple of a number can be divided by it exactly, with no remainder. For example, 12 is a multiple of 4 because 12 ÷ 4 = 3 exactly.

Check which property is shared by three of the numbers, then find the one that breaks the pattern.

NCERT anchor: CBSE Class 4 logical reasoning; Maths 4 odd/even numbers and multiples

Which number does NOT belong? 2, 4, 6, 9

Step 1 — 2, 4 and 6 are even numbers.
Step 2 — 9 is an odd number.
Answer: **9**

Which number does NOT belong? 5, 10, 15, 12

Step 1 — 5, 10 and 15 are all multiples of 5 (5x1, 5x2, 5x3).
Step 2 — 12 is not a multiple of 5.
Answer: **12**

Mistake	Why it happens	Fix
Confusing odd/even with multiples	Not checking both properties	Test both odd/even AND multiples before deciding
Wrong multiplication table	Forgetting a multiple in the sequence	Write out the multiplication table on scratch paper
Picking the largest/smallest number	Assuming size matters instead of the property	Focus on the shared property, not the number's size
Rushing the check	Not verifying with division	Divide each number to confirm it is a multiple

Which number does NOT belong? 3, 5, 7, 8
Which number does NOT belong? 4, 8, 12, 10
Which number does NOT belong? 9, 18, 27, 25
Stretch: Which number does NOT belong among 12, 24, 36, 30? (Hint: check multiples of 12.)

Revision tip: Keep the multiplication tables of 2 to 10 handy — they help you quickly spot multiples in classification questions.

Open the Practice tab for graded questions on Number Classification.