Final answer:
The number 5.8 rounded to the greatest place value rounds up to 6 because the tenths digit (8) is greater than 5.
Step-by-step explanation:
The question '5.8 estimated to the greatest place value' refers to the concept of rounding a number to the largest place value. Here we would look at the number 5.8 which is a decimal with one digit after the decimal point. Since 5 is in the ones place and 8 is in the tenths place, the greatest place value for 5.8 is the ones place. If we round 5.8 to the ones place, we simply look at the tenths digit, which is 8 in this case. Because 8 is greater than 5, we would round up. Therefore, 5.8 rounded to the greatest place value is 6.