Answer:
Explanation:
1. For the first equation, we can round 73 to 70, 28 to 30, and
70 x 30 is 2100.
2. For the second equation, we can round 58 to 60, 32 to 30, and
60 x 30 is 1800.
3. For the third equation, we can round 23 to 20, 42 to 40, and
20 x 40 is 800.
4. For the final equation, we can round 94 to 90, 56 to 60, and
90 x 60 is 5400.