Step-by-step Explanation (Very Simple)
Question: The digits having only two lines of symmetry are _____ and _____.
Answer: 0 and 8.
What is a “line of symmetry”?
- A line of symmetry is a line that splits a shape into two equal halves.
- When you fold the shape on that line, both sides match exactly.
Types of lines of symmetry we will check
- Vertical line: a line going up and down.
- Horizontal line: a line going left and right.
How we will test each digit
- Imagine the digit is written in block style (like on a digital clock).
- Check if a vertical fold makes two equal halves.
- Check if a horizontal fold makes two equal halves.
- Count how many such lines work.
Check for digit 0
- Try a vertical fold (through the middle). The two sides match. ✔️
- Try a horizontal fold (through the middle). The top and bottom match. ✔️
- So, 0 has exactly two lines of symmetry: vertical and horizontal.
Check for digit 8
- Try a vertical fold (through the middle). Left and right match. ✔️
- Try a horizontal fold (through the middle). Top and bottom match. ✔️
- So, 8 has exactly two lines of symmetry: vertical and horizontal.
Why not other digits?
Most other digits (like 1, 2, 3, 4, 5, 6, 7, 9) do not match perfectly when folded vertically or horizontally in block style. Some may have no line of symmetry, and some may have only one. But only 0 and 8 have two.
Final Fill-in
Answer: The digits are 0 and 8.
Extra: Quick reference table (block style)
| Digit |
Vertical Symmetry? |
Horizontal Symmetry? |
Total Lines |
| 0 | Yes | Yes | 2 |
| 1 | No/Depends on font | No | 0 |
| 2 | No | No | 0 |
| 3 | No | No | 0 |
| 4 | No | No | 0 |
| 5 | No | No | 0 |
| 6 | No | No | 0 |
| 7 | No | No | 0 |
| 8 | Yes | Yes | 2 |
| 9 | No | No | 0 |
Note: We are using simple block-style digits. In some fancy fonts, symmetry can look different. For school math, use the standard block form.