$\"\"$ \ \

The expression is, $\"\"$ .

Round to the nearest whole number then add.

328 rounded to the nearest whole number is 300.

879 rounded to the nearest whole number is 900. \ \

$\"\"$

The expression becomes: $\"\"$

$\"\"$ (Add: $\"\"$ )

So, $\"\"$

$\"\"$

The addition is about $\"\"$ .