Time is ticking to file your federal income tax return. As the April 15th deadline quickly approaches, Luis Garcia with the Internal Revenue Service says slow down. He says there are some common mistakes like unsigned returns, mismatched social security numbers, and incorrect math. There's a solution. Don't try to do it all in your head. Use a calculator. He also reminds folks that people who call you and claim to be the IRS and demand immediate payment are scam artists and should be hung up on.