It looks like you want to write out the number described by the words:

• twelve thousand
• twelve hundred
• twelve

Let's break it down:

• Twelve thousand = 12,000
• Twelve hundred = 1,200 (because 12 × 100 = 1,200)
• Twelve = 12

Now, add them all together: 12,000 + 1,200 + 12 = 13,212

Final number: 13,212

If you want it written in words, it is: Thirteen thousand two hundred twelve.