Bounds

When a quantity, such as length or height is measured, the measurement is never exact. Different tools and methods will give more or less accurate results.

You will learn to:

   - Find the lower and upper bounds of a number

Method

Suppose we have a book, and we measure it’s width to be 16cm to the nearest cm. The actual width could have been as little as 15.5cm, or upto, but not including, 16.5cm.

We can write this as:

15.5 ≤ width of book < 16.5

Method

Write down the upper and lower bounds for the length of a pen which has been measured as 14cm to the nearest cm.

1. Get half of the degree of accuracy, 0.5 cm in this case, and subract it from the original amount for the lower bound.

            14 - 0.5 = 13.5
   

2. Add it on for the upper bound.

            14 + 0.5 = 14.5 
   

3. Write it out. 13.5 ≤ Length