Which one is correct grammatical?
- Give me 5 kg of Sugar.
- Give me 5 kg Sugar.
What is the difference between above sentences?
"Give me five kilograms of sugar."
When put in written form as representations of speech, small whole numbers of ten or less should be written out ("five"), and simple units should be spelled out ("kilograms"). Also, the the word "of" should be included.
In a list of multiple items that is written but not spoken, you may use abbreviations and omit the word "of":
5 kg sugar
1 kg salt
0.1 kg onion powder
If you are writing a technical document that is meant to be read and doesn't represent speech, you can use written numbers and units (5 kg).
Note that "sugar" should not be capitalized.
Obviously, the difference is that one has of in it and the other doesn't!
In speech, we would say "Five kilos of sugar", but in writing, for example in a recipe or a list, we would use "5 kg sugar".