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Learning Objectives

CollegeBoard Requirements for Binary

DAT-1.A: Representing Data with Bits

Basic Information

  • Bit is short for binary__ digit, and represents a value of either 0 or 1.
    • A byte is 8 bits.
  • Sequences of bits are used to represent different things.
    • Representing data with sequences of bits is called abstraction___.

Practice Questions:

  1. How many bits are in 3 bytes? 24

  2. What digital information can be represented by bits? 0 and 1

  3. Are bits an analog or digital form of storing data? What is the difference between the two? digital, digital is only 0 or 1, but analog can be a range of numbers

Examples

  • Boolean variables (true or false) are the easiest way to visualize binary.
    • 0 = False
    • 1 = True
import random

def example(runs):
    # Repeat code for the amount of runs given
    while runs > 0:
        # Assigns variable boolean to either True or False based on random binary number 0 or 1.
        boolean = False if random.randint(0, 1) == 0 else True 

        # If the number was 1 (True), it prints "awesome."
        if boolean:
            print("binary is awesome")
            
        # If the number was 2 (False), it prints "cool."
        else:
            print("binary is cool")
            
        runs -= 1
     
# Change the parameter to how many times to run the function.   
example(10)
binary is awesome
binary is cool
binary is cool
binary is cool
binary is cool
binary is awesome
binary is cool
binary is awesome
binary is awesome
binary is awesome

DAT-1.B: The Consequences of Using Bits to Represent Data

Basic Information

  • Integers are represented by a fixed number of bits, this limits the range of integer values. This limitation can result in overflow__ or other errors.
  • Other programming languages allow for abstraction only limited by the computers memory.
  • Fixed number of bits are used to represent real numbers/limits

Practice Questions:

  1. What is the largest number can be represented by 5 bits? 32

  2. One programing language can only use 16 bits to represent non-negative numbers, while a second language uses 56 bits to represent numbers. How many times as many unique numbers can be represented by the second language? 2^56 - 2^16 = 2^40

  3. 5 bits are used to represent both positive and negative numbers, what is the largest number that can be represented by these bits? (hint: different than question 1) 8

Examples

import math

def exponent(base, power):
    # Print the operation performed, turning the parameters into strings to properly concatenate with the symbols "^" and "=".
    print(str(base) + "^" + str(power) + " = " + str(math.pow(base, power)))

# How can function become a problem? (Hint: what happens if you set both base and power equal to high numbers?)
exponent(5, 2)

#A function like this can become a problem if both the base and power parameters 
# are set to very high numbers. 
# math.pow() function used to calculate the exponentiation may result in a very 
# 
# large number that exceeds the maximum size that can be represented by the data 
# type being used (e.g., float or int). In such cases, the result may be inaccurate 
# or even cause an error, depending on the language and environment being used. It is 
# important to consider the limitations of the data types being used and the potential 
# range of values that the function may receive as input.
5^2 = 25.0

DAT-1.C: Binary Math

Basic Information

  • Binary is Base 2, meaning each digit can only represent values of 0 and 1.
  • Decimal is Base 10, meaning eacht digit can represent values from 0 to 9.
  • Conversion between sequences of binary to decimal depend on how many binary numbers there are, their values and their positions.

Practice Questions:

  1. What values can each digit of a Base 5 system represent? values of 0,5,25,125, so on

  2. What base is Hexadecimal? What range of values can each digit of Hexadecimal represent? base 6, 0,6,36,etc.

  3. When using a base above 10, letters can be used to represent numbers past 9. These letters start from A and continue onwards. For example, the decimal number 10 is represented by the letter A in Hexadecimal. What letter would be used to represent the Base 10 number 23 in a Base 30 system? What about in a Base 50 system? M, M

Examples

  • Using 6 bits, we can represent 64 numbers, from 0 to 63, as 2^6 = 64.
  • The numbers in a sequence of binary go from right to left, increasing by powers of two from 0 to the total amount of bits. The whole number represented is the sum of these bits. For example:
    1. 111111
    2. 2^5 + 2^4 + 2^3 + 2^2 + 2^1 + 2^0
    3. 32 + 16 + 8 + 4 + 2 + 1
    4. 63
  • Fill in the blanks (convert to decimal)

    1. 001010 = 18_ 2 + 2^3
    2. 11100010 = 226_ 2 + 2^5 + 2^6 + 2^7
    3. 10 = 3_ 1 + 2
  • Fill in the blanks (convert to binary)

    1. 12 = _110__ 12/6= 0 3/2 = 1 1/2 = 1
    2. 35 = 100011_
    3. 256 = _100000000__

Hacks & Grading (Due SUNDAY NIGHT 4/23)

  • Complete all of the popcorn hacks (Fill in the blanks + run code cells and interact + Answer ALL questions) [0.3 or nothing]
  • Create a program to conduct basic mathematical operations with binary sequences (addition, subtraction, multiplication, division) [0.6 or nothing]
    • For bonus, program must be able to conduct mathematical operations on binary sequences of varying bits (for example: 101 + 1001 would return decimal 14.) [0.1 or nothing]
def binary_addition(binary1, binary2):
    max_len = max(len(binary1), len(binary2))
    binary1 = binary1.zfill(max_len) # # method so binary numbers will have zeros on the
    #left so that they have the same length as the maximum length.
    binary2 = binary2.zfill(max_len)
    result = ''
    track_carry = 0
    for i in range(max_len - 1, -1, -1): # goes through each digit in the two binary numbers from the right to the left.
        r = track_carry
        r += 1 if binary1[i] == '1' else 0 #if the current digit in binary1 is 1, 1 is added to 'r'
        r += 1 if binary2[i] == '1' else 0 # If the current digit in binary2 is 1, another 1 is added to 'r'. 
        result = ('1' if r % 2 == 1 else '0') + result
        track_carry = 0 if r < 2 else 1
    if track_carry != 0:
        result = '1' + result
    return result


# takes two binary sequences as input and returns their difference in decimal form.
def binary_subtraction(binary1, binary2):
    max_len = max(len(binary1), len(binary2))
    binary1 = binary1.zfill(max_len)
    binary2 = binary2.zfill(max_len)
    result = ''
    borrow = 0
    for i in range(max_len - 1, -1, -1):
        if binary1[i] == '0':
            if binary2[i] == '0':
                result = ('1' if borrow == 1 else '0') + result
                borrow = 1 if borrow == 1 else 0
            else:
                result = ('0' if borrow == 1 else '1') + result
        else:
            if binary2[i] == '0':
                result = ('0' if borrow == 1 else '1') + result
            else:
                result = ('1' if borrow == 1 else '0') + result
                borrow = 1
    return str(int(result, 2))

# takes two binary sequences as input and returns their product in decimal form.
def binary_multiplication(binary1, binary2):
    result = '0'
    for i, bit1 in enumerate(reversed(binary1)): #iterate through the elements of x in reverse order, while also keeping track of the index of each element.
        if bit1 == '1':
            temp = bin(int(binary2, 2) << i)[2:]
            temp += '0' * i
            result = binary_addition(result, temp)
    return str(int(result, 2))


#takes two binary sequences as input and returns their quotient and remainder in decimal form.
def binary_division(dividend, divisor):
    dividend_int = int(dividend, 2)
    divisor_int = int(divisor, 2)
    quotient_int = dividend_int // divisor_int
    remainder_int = dividend_int % divisor_int
    quotient_binary = bin(quotient_int)[2:]
    remainder_binary = bin(remainder_int)[2:]
    return str(quotient_int), str(remainder_int)

# Taking user input
binary1 = input("Enter binary: ")
binary2 = input("Enter binary: ")

print("binary addition: ", binary_addition(binary1, binary2))
print("binary subtraction: ", binary_subtraction(binary1, binary2))
print("binary multiplication: ", binary_multiplication(binary1, binary2))
quotient, remainder = binary_division(binary1, binary2)
print("binary division - quotient: ", quotient)
print("binary division - remainder: ", remainder)
binary addition:  10000
binary subtraction:  0
binary multiplication:  345
binary division - quotient:  2
binary division - remainder:  1