Using inequality notation for errors in calculations

12 questions

1. An error interval for a number x shows the range of possible values of x. It is written as a\leq x < b. Explain what this means.
2. When a number, x, is rounded to the nearest integer the result is 63. Select the numbers which complete the error interval for x: \square \leq x <\square
3. When a number, x, is rounded to the nearest integer the result is 5. Select the numbers which complete the error interval for x: \square \leq x <\square
4. When a number, x, is rounded to the nearest integer the result is 10. Select the numbers which complete the error interval for x: \square \leq x <\square
5. Jun rounds a number to the nearest integer and the result is 5. Izzy rounds a number to 1 d.p. and the result is 5.0. Jun says, "We must both have rounded the same number." Is Jun correct?
6. x and y are both integers. x = 650 (rounded to the nearest 10) and y = 800 (rounded to the nearest 100). The greatest possible integer value of x+y is ___.
7. __________ are the digits in a number that contribute to the accuracy of the number. The first significant figure is the first non-zero digit.
8. When a number, x, is rounded to the nearest integer the result is 35. Select the numbers which complete the error interval for x: \square \leq x <\square
9. A long road is made up of 3 sub roads. The 1st road measures 35 m (2 s.f), the 2nd road is 41 m (2 s.f) and the 3rd road is 48 m (2 s.f). Find the error interval for the length x of the long road.
10. A wall is in an L-shape. All the lengths are given to 1 d.p or the nearest integer. Work out the error interval for the area of the wall.
11. A square has lengths in cm given to 1 decimal place. The error interval of the perimeter of the square is 31 \leq x <31.4 . Work out the length of the square correct to 1 d.p.
12. A square has lengths in cm to 1 decimal place. The error interval of the area of the square is 30.8025 \leq x <31.9225 . Work out the length of the square to 1 d.p.

License: OGL