Both candidates have bolstered their arguments with figures, statistics and percentages -- numbers that are likely to be the focus of the debates. Here's a look at some frequently cited figures:
8.1% The unemployment rate.
30 The number of months in which the country added private-sector jobs.
47% The now-famous proportion of the public that Romney said were "dependent" on the government and viewed themselves as "victims."
100% The proportion of the U.S. public that Romney says he will represent as president.
$5,000,000,000,000 This $5 trillion figure is the cost of Romney's proposals to cut taxes for the wealthy, Obama's campaign said. The president's claim that Romney would raise taxes on the middle class is driven by this estimate of GOP tax cuts.
$16,000,000,000,000 The amount of U.S. debt. Romney has tried repeatedly to get people focused on the $16 trillion debt after four years of an Obama presidency.
$2,000 The amount that Obama says middle-class taxes will go up if Romney is elected.
5 The number of days that Romney says the U.S. government knew about the terrorist connections to the attack in Benghazi, Libya, before acknowledging them.
$3.80 The average price of a gallon of gas. Romney has noted that gas was $1.84 a gallon when Obama took office.
$6,400 The additional amount that Obama says individual seniors would pay if Romney and his running mate, Rep. Paul Ryan, enacted their plans for reforming Medicare.
23 MILLION The number of Americans who are, in Romney's vernacular, "unemployed, underemployed or have stopped looking for work."
46.2 MILLION Number of people in poverty
47th Where Massachusetts ranked in job creation during Romney's tenure as governor.
$17,000 The amount at which Romney says he might cap deductions after lowering income tax rates.
4 The number of Supreme Court justices older than 70, who might be candidates for replacement by the next president.
12 MILLION The number of new jobs Romney promises his economic plan will deliver during his first term. It's also the number of jobs that independent economists say would be created during the next four years if Obama's current policies are followed.
11 MILLION The number of illegal immigrants in the United States. Romney used to say they should "self-deport." But he has recently tried to soften his hard edge on immigration.
20% The size of the across-the-board tax rate cuts that Romney promises if he is elected.
NEW YORK TIMES