Place Value Modification: Changing Digits in 429

If you increase the tens digit in the number 429 by 1 and the hundreds digit by 2, then what number are you left with?

To solve this problem, we will modify the digits of the number 429 based on the given instructions:

• Step 1: Identify the digits in the number 429. The hundreds digit is 4, the tens digit is 2, and the ones digit is 9.
• Step 2: Increase the tens digit by 1. Therefore, the new tens digit is $2 + 1 = 3$.
• Step 3: Increase the hundreds digit by 2. Therefore, the new hundreds digit is $4 + 2 = 6$.
• Step 4: Construct the new number. The new number has a hundreds digit of 6, a tens digit of 3, and an unchanged ones digit of 9.

Therefore, the new number formed is $639$.

The correct answer to this problem is $639$, which matches choice 2.