1. Can any number be written in standard form?
Yes, any number however small or large can be written in standard form.
2. How does a calculator show standard form?
It varies from calculator to calculator but many show 3.45 × 102 as 3.45 02
3. What does the ENG button on a calculator do?
The ENG button converts between different metric units.
e.g. To change 5634 metres into kilometres press: 5.634 03
i.e. 5634 = 5.634 km
4. Is it necessary to show the (×100) part, when writing a number between 1 and 10 in standard form?
Yes, to be in standard form the number must include the ×100 part.