To estimate 33 percent of 87, you should round 33 percent to 30 percent and 87 to 90. Here's how that works:
- Round 33 percent to 30 percent.
- Round 87 to 90.
Next, think of 30 percent as three groups of 10 percent.
- Find 10 percent of 90: This is 9.
- So, 30 percent of 90 is 9 + 9 + 9 = 27.
Therefore, the correct explanation is: Round 33 percent to 30 percent and 87 to 90. Think of 30 percent as 10 percent + 10 percent + 10 percent. Find 10 percent of 90 as 9. So, 30 percent of 90 is 9 + 9 + 9, which is 27.