Help me name this alkene

The alkene is:

...............CH3
................|
CH3 - C = C - CH3
..........|
.........CH2
..........|
.........CH3

With all numbers in subscript. (Ignore the dots, it doesn't give the proper structure without them).
My book says it is 2,3-dimethylpent2-ene. But wouldn't it be 2ethyl3methylbut-2-ene?
If i'm wrong, could you explain why?

The parent chain starts at the CH3 on the bottom bit and goes up to the C, then all the way right to the CH3 at the far right. Counting all the Cs on that chain gives 5 Cs in total, which is why it's a "pent".

The 2,3-dimethyl- is so because alkyl groups are numbered so that they occupy the lowest positions, which along a chain of 5 happens to be 2 and 3 (in this case). It is dimethyl because each of these branches has only one carbon, hence, "methyl" and there are two of them hence "di".

Sorry, the parent chain starts at the right, not the bottom.

In chemistry when you are selecting the parent chain it should contain the maximum number of carbon as possible or the longest carbon chain is selected as parent chain
and about numbering the number of substituent when adding must be least as possible
in your book says 2 and 3 position contain methyl group and 2 position contains double bond adding all gets 2+2+3= 7
and so is your numbering but you dont have the longest carbon chain
yes the answer is of your book

It is 2,3- dimethy pent-2-ene , according to IUPAC system of nameculature , we have to choose the longest chain of carbon atoms to name the organic compound .

Your book is correct. the first rule for writing IUPAC name is
1) Take the LONGEST chain.
2) Start numbering from the end where functional group is nearest.
So the name of above molecule is 2,3 dimethylpent-2ene