Answer:
4,000
Explanation:
22 x 18 x 9
22 is closest to 20
18 is also closest to 20
9 is closest to 10
Equation: 20 x 20 x 10
20 x 20 = 400 x 10 = 4,000
All you have to do is know your numbers and know how to estimate.
If you understand it, this is why the answer is 4,000.
Thank you for having me answer this.