1. A factory produced 3,675 widgets on Monday and 4,025 widgets on Tuesday. Use mental math to find the total number of widgets produced. ___
2. To solve $1,500 + (500 + 820)$ by regrouping it as $(1,500 + 500) + 820$, which property of addition is applied?
3. A library has 2,450 fiction books and 1,580 non-fiction books. Use the 'Add On' strategy to find the total number of books. ___
4. Which expression shows a good first step to solve $5,990 + 2,345$ using a mental math strategy to make a thousand?
5. Use mental math to find the sum of three numbers by regrouping: $4,250 + 917 + 750 = \_\_\_.
6. A warehouse worker calculates the sum of $3,812 + 4,325$ by thinking '$3,812 + 4,000 = 7,812$, then $7,812 + 300 = 8,112$, then $8,112 + 20 = 8,132$, then $8,132 + 5 = 8,137$'. Which mental math strategy is this?
7. To solve $6,150 + 2,950$ mentally, you can calculate $6,100 + (50 + 2,950)$. What is the sum? ___
8. A charity raised 5,980 dollars from a bake sale and 3,420 dollars from a car wash. What is the total amount raised in dollars? ___
9. To add $7,462 + 1,050$ using the 'Add On' strategy, the first step is $7,462 + 1,000 = 8,462$. What is the next logical step?
10. A farmer harvested 2,995 pounds of potatoes and 4,178 pounds of carrots. Use compensation to find the total weight. The total weight is ___ pounds.