Åk 6–9

 5.2 Rounding Numbers Sometimes,  it’s important to calculate exact values of numbers, and sometimes it’s more practical to write an approximation.   For example, it would be impractical to indicate the distance between two cities in meters.  There is no practical use for this since it does not matter if the distance is 100 meters shorter or longer.  Instead, you express it in kilometers. I, Stockholm’s City Library there are 2,000,000 books.  In reality, there are not exactly 2,000,000 books but 2,103,405 of them.   For simplicity’s sake, we say 2,000,000. Foto: Fredrik Enander We can look at the cost of the tower and apartment building, ”The Turning Torso”, for example.  The total costs for the building was 1.3 billion crowns (1,300,000,000 SEK). Most likely the tower did not cost exactly that much, but there is no significance for the public to know exactly how many crowns the tower cost to build.  Instead, they rounded the number to the nearest hundred millions. Foto: Dan Gunnarsson 