When solving problems that involve multiple steps, rounding too early can affect the accuracy of the final answer. This is called premature rounding.

If values are rounded during intermediate steps, small rounding errors can build up and lead to a final answer that is noticeably incorrect. To avoid this, calculations should be carried out using the full values shown on the calculator, and rounding should only be done at the final step, unless the question states otherwise.

Consider the following example.

First calculate the exact value.

$$
4.8 \times 2.35 = 11.28
$$

Now suppose the intermediate result is rounded early to \( 11.3 \).

Using this rounded value in the next step:

$$
11.3 \div 3 = 3.7666
$$

If the exact value is used instead:

$$
11.28 \div 3 = 3.76
$$

The two answers are different because rounding was done too soon.

In longer calculations, especially those involving bounds, percentages or measurements, premature rounding can cause the final answer to fall outside the correct range.

To maintain accuracy, always keep full calculator values throughout the working and round only once, at the end, to a sensible degree of accuracy based on the context of the problem.

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