Quiz 2

What is the difference between rounding 57,213 to the thousands place and the ten thousands place?

A 3,000 57,213 rounded to the thousands place is 57,000. 57,213 rounded to the ten thousands place is 60,000. The difference in these numbers is 3,000.

Which of the following is the best estimate for 6,189 × 485?

A 3,000,000 6189 ≅ 6000 = 6 × 1000 and 485 ≅ 500 = 5 × 100. The product of 6 and 5 is 30. The product of 1000 and 100 is 100000. The approximate value of 6189 ✕ 485 is 30 × 100,000 = 3,000,000.

Which symbol most accurately reflects the relationship between the two numbers below? −3/4 □ −8/11

B < Fractions can be quickly compared once they have a common denominator. The smallest common denominator of both fractions is 44. Multiply −3/4 by 11/11​ to get −33/44. Multiply −8/11 by 4/4 to get −32/44. The fraction −32/44 has the greater numerator, so its equivalent form −8/11 is the greater fraction.

The expression 3 to the -3 x 3 square is equivalent to:

C 1/3 This expression requires that the exponents be added together, resulting in 3 to the -1 power = one third

Which of the following is the product of -2 + 4i and 1+ 3i in simplest form?

C -14 -2i (4i -2)(3i + 1) = 12i 2 - 6i + 4i -2 using foil. Simplify the first term by substituting i 2 = -1 to obtain -12 - 6i + 4i -2. Combine like terms: -2i - 14.

If the value of A equals 1/5 and the value of B equals 1/2, which of the following equals C?

C 21/25 Point A is equal to 1/5 therefore each hash mark is equal to 1/5. C is closest to 4/5, however it is slightly more. 4/5 = 20/25 so 21/25 is the best answer.

12π ÷ 9 is approximately equivalent to:

C 4 Recall that a good estimation for π is 3. So, 12π ≈ 36, which divides by 9 into 4.

Which of the following summative assessment prompts on fractions will best reveal whether a student understands fraction applications in the real world?

C Write a story problem without using any fractions in the story, but which requires the use of fractions in the solution. Then solve the problem showing your work. Having students write and solve a story problem indicates whether they understand the context of fractions in the real world.

Which number below has an exponential form of 7 × 10 to the 9th power

D 7,000,000,000 Seven billion in exponential form is 7 × 10 to the 9th power. When converting this number to standard notation, the decimal will move to the right nine places.

There are 110 people in line to ride the Shark Splash roller coaster. The ratio of girls to boys in line is 6 to 14. How many people in line are boys?

D 77 The ratio 6:14 can be reduced to 3:7. This means that out of every 10 people, 3 are girls and 7 are boys. There are 11 sets of 10 in this population (11 x 10 = 110). Therefore, 7 boys x 11 sets = 77 total boys.

What is the place value of the "5" in the number 15,436,129?

D millions In a base 10 system, each place location for a number has a value that is a power of 10. Specifically, the ones place is properly understood to be 10⁰ (because any nonzero number raised to the zero power equals 1). The tens place is 10¹, the hundreds place is 10², the thousands place is 10³, etc. When a digit is in a specific position, its value is equal to the product of that digit and the power of 10 that is assigned to its position. In the direction of the positive powers of ten, the units are ones, tens, hundreds, thousands, ten thousands, hundred thousands, millions, ten millions, hundred millions, billions, etc. Therefore, in the number 15,436,129, the 5 represents 5 × 10⁶, or 5 × 1,000,000 = 5,000,000, which is pronounced 5 million. Therefore, the 5 is in the millions place.

Which of the following is not a rational number?

D π The value of pi (π) never ends and does not repeat, making it irrational.