Question

to make 77 + 48 easier to solve, lou decides to first add on from 77 to get to the next ten.
add on to get to 80.
77 + 3 = 80
how much more does lou need to add on?
77 + 48
=77 + (3 +? )

Explanation:

Step1: Find remaining value in 48

Since we used 3 to get from 77 to 80, calculate $48 - 3 = 45$.

Step2: Fill the first blank

The blank for $77 + \square = 80$ is 3, as shown.

Step3: Rewrite the addition

Break 48 into 3 and 45, so $77 + 48 = 77 + (3 + 45)$.

Step4: Confirm total added value

After adding 3 to reach 80, we need to add 45 more.

Answer:

1. The blank for $77 + \square = 80$: 3
2. The amount Lou needs to add on after 3: 45
3. The blank in $77 + 48 = 77 + (3+ \square)$: 45