3. Computing with Numbers

Question 1

True or False

Information that is stored and manipulated by computers is called data.

Answer 1

True

The information that is stored and manipulated by computer programs is generically referred to as data (p. 57)

Question 2

True or False

Since floating-point numbers are extremely accurate, they should generally be used instead of ints.

Answer 2

False

Another difference between ints and floats is that the float type can only represent approximations to real numbers. Since float values are not exact, while ints always are, your general rule of thumb should be: If you don’t need fractional values, use an int. (p. 59)

Question 3

True or False

Operations like addition and subtraction are defined in the math library.

Answer 3

False

Python supports the usual mathematical operations on numbers (p. 59)

Question 4

True or False

The number of possible arrangements of n items is equal to n!.

Answer 4

True

The factorial of a whole number n is defined as n! = n(n -1) (n-2) … (1). (p 69)

Question 5

True or False

The sqrt function computes the squirt of a number.

Answer 5

False

The sqrt functions computes the square roots of a number.

Question 6

True or False

The float data type is identical to the mathematical concept of a real number.

Answer 6

False

It is an approximation.

Question 7

True or False

Computers represent numbers using base-2 (binary) representations.

Answer 7

True

Inside the computer, ints are stored in a fixed-sized binary representation (p. 72)

Question 8

True or False

A hardware float can represent a larger range of values than a hardware int.

Answer 8

True

Question 9

In order to use functions in the math library, a program must include

a) a comment
b) a loop
c) an operator
d) an import statement

Answer 9

d) an import statement

Question 10

The value of 4! is

a) 9
b) 24
c) 41
d) 120

Answer 10

b) 24

Question 11

The most appropriate data type for storing the value of pi is

a) int
b) float
c) irrational
d) string

Answer 11

b) float

Question 12

The number of distinct values that can be represented using 5 bits is

a) 5
b) 10
c) 32
d) 50

Answer 12

c) 32

Question 13

In a mixed-type expression involving ints and floats, Python will convert

a) floats to ints
b) ints to strings
c) both floats and ints to strings
d) ints to floats

Answer 13

c) both floats and ints to strings

Question 14

Which of the following is not a Python type-conversion function?

a) float
b) round
c) int
d) abs

Answer 14

b) round

Question 15

The pattern used to compute factorials is

a) accumulator
b) input, process, output
c) counted loop
d) plaid

Answer 15

a) accumulator

Question 16

In modern Python, an int value that grows larger than the underlying hardware int

a) causes an overflow
b) converts to float
c) breaks the computer
d) uses more memory

Answer 16

d