If you are having trouble with ratios, turn them into fractions.
ex; 3 : 5 = 3/5, 8 : 10 = 8/10, 6 : 15 = 6/15
After you have turned all of your ratios into fractions, you can find a common denominator for all the fractions.
ex; 3/5, 8/10, 6/15 ⇒ 3/5, 4/5, 2/5
Now it you can easily order the ratios from least to greatest.
ex; 6 : 15, 3 : 5, 8 : 10
So based on place values, the One's place is occupied by 4. To round to this digit, you go one number to the right. If that number is 5 or higher, you add one to 4. If it is less than 5, you don't add any to 4. Since 7 is greater than 5, you add 1 to 4, giving you 5, since you can now remove all the other numbers to the right.
5.
Answer:
I am not sure if this is right but the answer is
The area of a circle with circumference 18π is 254.5
The numbers that would be smaller would be the two with the difference of 26.
27-1=26 where as, if you were to use a 1 in each, 99+1= 100. Therefore 27 and 1 (28) is less than 99 and 1 (100).