Image Credit: John BramleyIf George Washington and Abraham Lincoln were still around today, surely they’d spend Presidents’ Day weekend at the movies. They’d even split a 1,000-calorie large popcorn, I imagine. This holiday weekend sees three new releases join a healthy pack of holdovers. Teens and young adults have I Am Number Four, DreamWorks’ alien-meets-Twilight-via-Michael Bay extravaganza. Adults will be able to watch the world’s most badass Irishman, Liam Neeson, in the stolen-identity thriller Unknown. And Big Mommas: Like Father, Like Son will count on fans of the prior two Big Momma movies to turn out. Add in last weekend’s strong releases, like Just Go With It and Gnomeo & Juliet, and you have one crowded multiplex. Here’s how I think the four-day weekend will play out:

1. I Am Number Four: $29 million

The first DreamWorks project to be released by Disney (through its Touchstone Pictures label), this PG-13 sci-fi adventure stars young British actor Alex Pettyfer as a teenage alien who, naturally, has inherited some pretty cool powers. Relocating to Earth after his home planet was destroyed, Pettyfer falls in love with a local girl (Glee‘s Dianna Agron) while trying to evade the evil Mogadorians (more aliens). Equal parts action film (Michael Bay is a producer) and teen romance, I Am Number Four should have no trouble drawing a young crowd of both genders, and will benefit from playing on 228 IMAX screens. Last Presidents’ Day weekend, the similarly themed Percy Jackson and the Olympians: The Lightning Thief opened to $38.7 million. But Number Four will more likely fall in the Presidents’ Day range of Jumper, which debuted to $32.1 million in 2008.

2. Unknown: $22.5 million

After I Am Number Four, it becomes extremely challenging to predict how the rest of the top five will finish. I think Unknown has the best shot at second place, as the PG-13 thriller is being marketed as a close relative of 2009’s Taken, which opened with $24.7 million and went on to collect $145 million. Unknown, which cost only $31 million to produce, is tracking well with older moviegoers, but that audience segment doesn’t necessarily rush to the theater. Still, I think there’s enough interest out there that the film will wind up with a four-day gross in the low-20s.

3. Gnomeo & Juliet: $22 million

This G-rated animated musical surpassed everyone’s expectations last weekend by earning $25.4 million. With no new family movies entering the fray, the Disney flick, which scored a “B+” rating from CinemaScore moviegoers, should hold up well this holiday weekend.

4. Just Go With It: $21.5 million

The Adam Sandler-Jennifer Aniston romantic comedy has been topping the box office throughout the workweek and garnered an “A-” CinemaScore, so there’s a chance the PG-13 movie won’t suffer the typical Sandler drop of 50 percent. Still, if I had to choose between the comic and a Shakespearean garden gnome this weekend, I’m placing my chips with the latter.

Who knows? The first Big Momma’s House registered $25.7 million its debut weekend in 2000 en route to $117.6 million. The sequel, Big Momma’s House 2, opened to an even larger $27.7 million in 2006, but quickly plummeted after that to finish its run with just $70.2 million. This looks like a franchise with diminishing returns, and Martin Lawrence hasn’t starred in a hit since 2007’s Wild Hogs. Regardless, I wouldn’t be surprised if this PG-13 threequel somehow landed in second place this weekend.