5/12 Numbers and Quantity

Which expression, when simplified, results in an irrational number?

• $4\div10$

• $3-\frac{1}{3}$

• $4.25+\sqrt{9}$

• $\sqrt{8}\times2$

Consider the numbers 4 and $\sqrt{5}$  . Which operation(s) will result in an irrational number? 

• the sum only

• the product only

• neither the sum nor the product

• both the sum and product

• The sum is rational because the sum of an irrational number and an irrational number is sometimes rational.

• The sum is rational because the sum of two non-zero rational numbers is always rational.

• The sum is irrational because the sum of an irrational number and a non-zero rational number is irrational.

• The sum is irrational because the sum of two irrational numbers is sometimes irrational.

The band is doing a fundraiser for their trip to Myrtle Beach this spring. All money earned is to be divided equally among the 32 people who are participating in the fundraiser and will pay for part of their trip, which costs $535.

What is a reasonable estimate for the amount of money that must be raised so that half of each of the 32 students’ trips are covered?

• $268

• $535

• $8,560

• $17,120

A biologist measured the mass of a baby elephant. In reporting her findings, the biologist will most likely use units of ________________.

• micrograms

• milligrams

• grams

• kilograms

As part of a science activity, Salina rolls a ball weighing 30 ounces down a wooden ramp. It takes 3.5 minutes to roll the ball down the ramp sloped at an angle of 42°.

If the distance covered by the ball is 85 feet, which unit best describes the speed of the ball?

• pounds per feet

• feet per pound

• feet per minute

• degrees per minute

Helena is a contractor building a 3-story house. What is the best estimate for the height of the house, in feet, excluding any attic or roofing on the house?

• 3 ft

• 18 ft

• 30 ft

• 48 ft

Ella is collecting data about the numbers of hours teenagers spend on computers each day. Which values represent the best scale for a box plot of the numbers of hours teenagers spend on computers each day?

• −5, 0, 5, 10, 15

• 0, 4, 8, 12, 16

• 0, 12, 24, 36, 48

• 5, 10, 15, 20, 25

Steven needs to unload a truck containing boxes filled with video consoles. He wants to determine the time required to unload the truck.

Which quantity will help Steven to determine the time required?

• the number of boxes in the truck

• the number of boxes in the truck and the weight of each box

• the time taken to unload a box

• the time taken to unload a box and the number of boxes in the truck

For a holiday celebration, Andre’s neighborhood is planning a fireworks show. Andre is trying to estimate the length of time the fireworks show will take.

What is a valid estimate?

• 20 hours

• 20 minutes

• 20 nanoseconds

• 20 seconds