# Bytes - the unit of storage - Answers

**Q1.** Write out the following numbers in approximate numbers of bytes. The first few have been done for you.

Number |
Approx number of bytes |

a. 5 Kbytes | 5 000 bytes approximately. |

b. 6 Mbytes | 6 000 000 bytes approximately. |

c. 20 Gbytes | 20 000 000 000 bytes approximately. |

d. 35 Kbytes | 35 000 bytes approximately. |

e. 55 Mbytes | 55 000 000 bytes approximately. |

f. 130 Kbytes | 130 000 bytes approximately. |

g. 1000 Mbytes | 1000 000 000 bytes approximately. |

h. 3 Tbytes | 3 000 000 000 000 bytes approximately. |

i. 6000 Kbytes | 6 000 000 bytes approximately. |

**Q2. **Calculate the exact number and an approximation. The first few have been done for you.

Number |
Exact |
Approx |

a. 6 * 2^{10} |
6 144 bytes | 6 Kbyte |

b. 15 * 2^{12} |
61 440 bytes | 61 Kbytes |

c. 9 * 2^{14} |
147 456 | 147 Kbytes |

d. 3 * 2^{19} |
1 572 864 | 2 Mbytes |

e. 4 * 2^{25} |
134 217 728 | 134 Mbytes |

f. 17 * 2^{26} |
1 140 850 688 | 1 Gbyte |

g. 8 * 2^{32} |
34 359 738 368 | 34 Gbytes |

h. 2 * 2^{34} |
34 359 738 368 | 34 Gbytes |

i. 1 * 2^{40} |
1 099 511 627 776 | 1 Tbyte |

**Q3. **Write out these numbers of bytes in words. The first few have been done for you.

Number |
Description |

a. 34 520 | Thirty four thousand, five hundred and twenty bytes. |

b. 751 002 | Seven hundred and fifty one thousand and two bytes. |

c. 3 201 630 | Three million, two hundred and one thousand, six hundred and thirty bytes. |

d. 34 456 789 | Thirty four million, four hundred and fifty six thousand, seven hundred and eighty nine bytes. |

e. 110 000 000 | One hundred and ten million bytes. |

f. 220 000 000 | Two hundred and twenty million bytes. |

g. 1 000 000 000 | one billion bytes. (thousand million = UK = USA = some debate!) |

h. 23 000 602 022 | 23 billion, six hundred and two thousand and twenty two bytes. |

i. 1 000 000 000 000 | 1 trillion bytes (again, some debate about UK trillions and USA trillions). |

**Extension work**Use the Internet to find the answers to the following:

**a)**The next four in the sequence: Kilobyte, Megabyte, GigaByte, Terabyte are Petabyte, Exabyte, Zettabyte and Yottabyte.

**b)**A group of 4 bits is called a nibble.

**c)**The term 'bit' comes from

*inary dig*

**b****.**

*it***d)**You can have quite a debate here about how you compare different but similar products like laptops and what criteria you might use. Most students will not think about what they actually want to do with the product before making some kind of selection. There is a whole lesson on selecting criteria and being objective. It would be interesting to get students to see how different reviewers compare similar products like laptops and getting different groups to evaluate the same products based on criteria. Trying to get different groups to agree e.g. 10 features they will all use to compare laptops might take half a lesson!

**e)**Chromebooks are interesting when compared to laptops. Most only come with a small amount of SD storage instead of a hard drive.

**f)**Private research, which should be close to most students' hearts!