Silvio completed this addition problem. Why did Silvio place a number above the 1 in 142?
142
+93
235
The sum of 4 tens and 9 tens is 13 tens, which is
regrouped as 1 hundred and 3 tens.
Ninety-three rounded to the nearest hundred is 1
hundred.
One hundred forty-two rounded to the nearest
hundred is 1 hundred.
The sum of 4 tens and 9 tens is 13 tens, which is
regrouped as 1 ten and 3 hundreds.

Mercury poisoning is dangerous overload of mercury within the body. a major source of mercury within the body, a major source of mercury poisoning is consuming fish that contain mercury. certain fish are more prone to having higher levels of mercury than others. the pie chart shows the distribution of four breeds of fish at a hatchery. the hatchery has approximately 6,000 fish. a biologist from the centers for disease control and prevention randomly test 5% of each breed of fish for mercury content. her findings are shown in the following table. based on the biologist's findings, if a single salmon is randomly selected from those that were tested, what is the probability that this particular fish would have a dangerous mercury level? a) 0.001 b) 0.004 c) 0.02 d) 0.08

What is the volume of this square pyramid?

Which system of linear inequalities is represented by the graph?