Turbotax determined I owe tax,
The program gives me

Form 1040-V payment voucher which has the whole tax due by April 15.

And 4 forms 1040-ES payment vouchers, each with a number,
Due April 15, June 15, Sept 15, and Jan 18 2011. The 4 forms has the same money and the total is $119 less than
The money specified in Form 1040-V.

My question is, is this optional to pay the total at once or 4 times,
And why the total is not the same ?

The 1040-V amount is the amount you owe for taxes on your 2009 tax return. This is due to the IRS by April 15, 2010, and is based on your income and taxes withheld in calendar year 2009.

The 1040-ES forms are estimated payments that the program thinks you shoud pay in 2010 against your 2010 taxes. If it appears that you're going to owe money in April 2011 on your 2010 income, you are required to "pay as you go" throughout the year. So TurboTax takes a stab at estimaitng the amount you should pay each quarter so that come April 2011 you don't get hit with an interest charge for underayment. It divides the total amount it thinks you owe for the 2010 taxes into 4 equal payments, and prints the forms out for you.

Bottom line - pay the 2009 1040-V amount now, and also pay the 4 estimated payments for 2010 as the program suggests each quarter.