16 / 3
You could use 250 and 750.
I would use 40 for the 38 and 50 for the 51. 90 would be my estimate.
805 and 1/ 3rd
how you would use the scale in miles to estimate to total area of Madagascar
You could use a demand chart to estimate this.
The answer depends on what you want to use the estimate for. If it is being added to 1 billion, I would estimate it as 0. If adding to 25000, I would estimate it as 15000 and if adding to 0.075, I would leave it as it is.
The front end estimate is 600. But estimating a single number, in isolation and without context, is a complete waste of time. If I had to add 558 to 1 trillion, I would estimate it as 0. If I had to add 558 to 0.0000000001, I would use the number as given - not use an estimate.Also, if I had to divide 558 by 5, I would estimate it as 560 since 560/5 = 112 whereas if I had to divide it by 30 I would go for 570 since 570/30 = 19.
You would use water displacement (ie volume)
5.6261
The front end estimate is 800.However, if I needed to add 750 to 1 billion, I would estimate 750 by 0 while if I wanted to add 750 to 0.001, I would use 750 as it is - not an estimate.
The front end estimate is 30. But estimating a single number, in isolation and without context, is a complete waste of time. If I had to add 33 to 1 trillion, I would estimate it as 0. If I had to add 33 to 0.0000000001, I would use the number as given - not use an estimate. Also, for multiplication, I might estimate it by 33.33... and then use 100/3 for calculations.
No because you would not use it as an estimate.