10, 100, 1,000? Um... I don't really understand but lemme take a shot at it. Hmmm... So, 12×x
x=? 3×40=12
So this probably means: 12×3=36 and the estimate of 36 would be 34?
To find your answer, multiply 1.5 by 2.5 since there are 2.5 cm in an inch, and there are 1.5 inches.
You would get 3.75.
Therefore, the paperclip is 3.75 centimeters long.
Hope this helps!
I recommend Desmos Graphing Calculator for this
Add and divide by 2 remembering the key 543+539= 546