NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 9: Symmetry and Practical Geometry - Fill in the Blanks

Question 30

Step-by-step explanation (very simple):

What is a line of symmetry?
A shape has a line of symmetry if it can be folded along a line and both halves match exactly.

1. List the digits from 0 to 9:
   0, 1, 2, 3, 4, 5, 6, 7, 8, 9
2. Check each digit for symmetry (using the usual printed font):
   • 0 → has two lines of symmetry (vertical and horizontal).
   • 8 → has two lines of symmetry (vertical and horizontal).
   • 3 → has one line of symmetry (horizontal) in the standard printed style we are using.
   • 1 → no line of symmetry (top and bottom strokes usually differ).
   • 2 → no line of symmetry.
   • 4 → no line of symmetry.
   • 5 → no line of symmetry.
   • 6 → no line of symmetry.
   • 7 → no line of symmetry.
   • 9 → no line of symmetry.
3. Count the digits with at least one line of symmetry:
   These are 0, 8 (two lines each) and 3 (one line).
   So the number of digits that do have symmetry is 3.
4. Find how many have no line of symmetry:
   Total digits = 10.
   Digits with symmetry = 3.
   Therefore, (10 - 3 = 7)
5. List the digits with no line of symmetry:
   1, 2, 4, 5, 6, 7, 9

Answer: The number of digits having no line of symmetry is 7.