Add a single digit to any 3-digit number (timed)
Add mentally a single digit to a 3-digit number.
Add a single digit to any 3-digit number (timed)
Add mentally a single digit to a 3-digit number.
![Preview of 'Add a single digit to any 3-digit number (timed)'](https://content.urbrainy.com/6923/97294191/thumbnail_xlarge/add-a-single-digit-to-a-3-digit-number-timed-1690043124.png)
Add mentally a single digit to a 3-digit number.
Add mentally a single digit to a 3-digit number.