Ruby program that prints a multiplication table for numbers up to your input. For example 12 x 12 fields.

multiplication_table.rb

def tbl max
    for y in (1..max) do
        for x in (1..max) do
            sol = y*x
            if sol < 10
                print "#{sol}    "
            elsif sol < 100
                print "#{sol}   "
            else
                print "#{sol}  "
            end
        end
        print "\n"
    end
end

tbl 23 is the maximum to fit in the windows PowerShell window.

print (x*y).to_s.center(5)