Ruby Program to Print Multiplication Table

You can print a multiplication table in Ruby using a loop like 1.upto(10) { |i| puts "#{i} x #{n} = #{i * n}" } where n is the number you want the table for.

Examples

Inputn = 2

Output1 x 2 = 2 2 x 2 = 4 3 x 2 = 6 4 x 2 = 8 5 x 2 = 10 6 x 2 = 12 7 x 2 = 14 8 x 2 = 16 9 x 2 = 18 10 x 2 = 20

Inputn = 5

Output1 x 5 = 5 2 x 5 = 10 3 x 5 = 15 4 x 5 = 20 5 x 5 = 25 6 x 5 = 30 7 x 5 = 35 8 x 5 = 40 9 x 5 = 45 10 x 5 = 50

Inputn = 0

Output1 x 0 = 0 2 x 0 = 0 3 x 0 = 0 4 x 0 = 0 5 x 0 = 0 6 x 0 = 0 7 x 0 = 0 8 x 0 = 0 9 x 0 = 0 10 x 0 = 0

How to Think About It

To print a multiplication table, think of counting from 1 to 10 and multiplying each number by the chosen number. For each count, show the multiplication expression and the result. This repeats until the table is complete.

Algorithm

1

Get the number n for which to print the multiplication table

2

Start a loop from 1 to 10

3

For each number i in the loop, calculate i multiplied by n

4

Print the expression 'i x n = result'

5

Repeat until the loop ends

Code

ruby

puts "Enter a number to print its multiplication table:"
n = gets.to_i
1.upto(10) do |i|
  puts "#{i} x #{n} = #{i * n}"
end

Output

Enter a number to print its multiplication table:
5
1 x 5 = 5
2 x 5 = 10
3 x 5 = 15
4 x 5 = 20
5 x 5 = 25
6 x 5 = 30
7 x 5 = 35
8 x 5 = 40
9 x 5 = 45
10 x 5 = 50

Dry Run

Let's trace the program with input n = 3 through the code

1

Input number

User inputs 3, so n = 3

2

Start loop

Loop variable i starts at 1

3

Calculate and print

Print '1 x 3 = 3'

4

Next iteration

i becomes 2, print '2 x 3 = 6'

5

Continue until 10

Repeat until i = 10, printing each line

i	Expression	Result
1	1 x 3	3
2	2 x 3	6
3	3 x 3	9
4	4 x 3	12
5	5 x 3	15
6	6 x 3	18
7	7 x 3	21
8	8 x 3	24
9	9 x 3	27
10	10 x 3	30

Why This Works

Step 1: Getting input

The program asks the user for a number and stores it in n.

Step 2: Looping from 1 to 10

Using 1.upto(10) runs the loop 10 times, once for each multiplier.

Step 3: Printing each line

Inside the loop, it prints the multiplication expression and result using string interpolation.

Alternative Approaches

Using a for loop

ruby

puts "Enter a number:"
n = gets.to_i
for i in 1..10
  puts "#{i} x #{n} = #{i * n}"
end

This uses a for loop instead of upto; both are simple and readable.

Using times loop

ruby

puts "Enter a number:"
n = gets.to_i
10.times do |i|
  puts "#{i + 1} x #{n} = #{(i + 1) * n}"
end

Uses zero-based index, so we add 1 to i for correct multiplication.

Complexity: O(1) time, O(1) space

Time Complexity

The loop runs exactly 10 times, so time is constant O(1) regardless of input.

Space Complexity

No extra memory grows with input; space used is constant O(1).

Which Approach is Fastest?

All approaches run in constant time; choice depends on readability preference.

Approach	Time	Space	Best For
upto loop	O(1)	O(1)	Simple and readable
for loop	O(1)	O(1)	Familiar to many programmers
times loop	O(1)	O(1)	Zero-based indexing style