Look at the images below and estimate the size of the each object:
Can you match any of these measurements to the images?
2m, 0.0000002m, 400 000 000m, 0.02m, 0.0008m, 20 000 000m, 800 000 000 000 000 000 000m, 400m, 8 000m, 0.00000000000008m
What about the remaining images – can you estimate their size/ length/ distance in m?
After the session, print off Measurements and standard form cards (2 more sets of cards) and match them to the above objects/ measurements.
Now try the problems below:
1. Music downloads
John downloads a music track for five minutes to a file in MP3 format for his own use. What size (in Megabytes) will the MP3 file need to be?
If his MP3 player has a memory of 5 Gigabytes, calculate an estimate of the maximum number of album tracks he can store on his portable MP3 player. Show, by estimation, how to check your answer without using a calculator.
Information on downloading
During downloading music is sampled 44 100 times each second. The size of each of these samples is 16 bits. Before it is stored in MP3 format the file is compressed to make it smaller using a ratio of 12:1.
- 8 bits are equal to 1 byte
- 1 Megabyte (MB) is equal to 1 048 576 bytes
- 1 Gigabyte (GB) is equal to 1 073 741824 bytes
- 1 Gigabyte (GB) is equal to 1 024 Megabytes (MB)
2. Standard form problems
a. The mass of a hydrogen atom is 1.7 x 10-24 g. One litre of air contains 2.5 x 1022 atoms of hydrogen.
What is the mass of hydrogen in one litre of air?
b(i). The population of Portugal in 1986 was 1.025 x 107.
The number of working people in Portugal in 1986 was 4.48 x 106.
Calculate the percentage of people in Portugal who were working.
b(ii). In 1986, 9.98 x 105 people in Portugal were farm workers.
How many working people in Portugal were not farm workers?
Give your answer in standard form.
You can download Standard form problems ANSWERS here.