Adding One Ten and One Unit to 66: Place Value Problem with Base-10 Blocks

To solve this problem, we need to add one ten (10) and one unit (1) to the number 66.

We'll follow these steps to find the new number:

• Step 1: Start with the original number, $66$.
• Step 2: Add one ten. This means adding $10$ to $66$.
  $66 + 10 = 76$.
• Step 3: Add one unit to the result from Step 2. This means adding $1$ to $76$.
  $76 + 1 = 77$.

Therefore, after adding one ten and one unit to 66, the resulting number is $77$.