Addition Problem: Finding the Sum of 45 + 19 Blocks

To solve this problem, we need to find the total number of blocks after adding 19 blocks to an existing 45 blocks.

Step 1: Identify the numbers involved:

• Initial number of blocks: $45$
• Additional blocks: $19$

Step 2: Perform the addition calculation: $45 + 19 = 64$

Now, let's explain the addition in detail:

• Start by adding the ones place digits: $5 + 9 = 14$. Write down 4 and carry over 1 to the tens place.
• Next, add the tens place digits, along with the carry-over: $4 + 1 (carry) + 1 = 6$.

Thus, the total number of blocks is $64$.

The correct answer choice is: 4

Therefore, the solution to the problem is $64$.