I love free entertainment. I periodically do random searches for free stuff to do in DFW and see what comes up. I also check in with our favorite places to see if they have something special or new happening. Here are a few of our favorite free and cheap hot spots.
Ft Worth Zoo- half priced Wednesdays. We bring a lunch and snacks to save money. Avoid this place like the plague over spring break :)
Paradise Pond - indoor play areas with bounce house, dress up etc. It's $1 per person, only open Thurs and Fri in Grapevine
http://www.fbcgrapevine.com/groups/children/paradise-pond/
Ft Worth Museum of Science and History - I bought a membership and make it a play date(my friend also got a membership) about every other week. We pack a lunch and all three kids LOVE it (1, 4, and 5 y.o.), especially the play area. We went for a visit and they let us credit our tickets towards a membership after we saw the exhibits and decided if we would be back. My daughter is only 1 and gets in free, so I bought a 2 person member ship for me and my son for $65. We go pretty often and love our visits.
Ridgmar Mall has a great indoor toddler playground. It's free. Just go early because the kids seem to get bigger and rowdier as the day progresses.
The botanical gardens are free and they have a kids area. We picnic here often. In October the Monarch butterflies are migrating and they are everywhere...makes for a fin trip!
Glenview Baptist (in Haltom City)- great indoor playground. The cost is $1 per kid. You would have to check with them for the times...it's been a little while since we have been there.
Cabelas and Bass Pro make great trips. The kids love the aquarium. If you look online you can find the feeding times and schedule a trip around that.
Stockyard Station - cattle drive at 11:30 daily. We went during spring break and they had a free petting zoo that day.
Ft Worth Modern Art Museum is half priced on Wednesdays (free the first Sunday of the month). You may want to double check what exhibits they have running before you go - they are not always kid friendly, depending on your comfort level. I have been pleasantly surprised that those visits have gone well. I think and hope my 4 year old is learning how to behave in a museum. Sometimes we bring snacks and go eat outside near the water for a break (you have to cut through the restaurant to get here, but the staff always lets us through). And he loves to hear the echoes in the sculpture out front! We have been doing this trip since he was about a year old. (we used to go to this one a lot more when it was free on Wed.)
The US Treasury off 287 has a free tour. In all honesty we could have just spent the day riding the shuttle bus from the check-in point to the tour facility and our kids would have been absolutely thrilled. It's free and close. The kids (1, 3 and 4) did get a little bored with the tour, but he liked the hands on exhibits we played with before and afterward. Check the website...the rules are very strict about what you can bring with you.
Check with your local Rec center for deals too. Ours has certain days where they open the indoor pool to the public for just a few bucks. Makes a fun play date in the winter when you have the place to yourselves.
Story time at the local library is a weekly trip for us.
We are always visiting local parks...I check the parks and rec websites to peruse the parks and see what's available before we head out. We try to go to a different park each time to keep things interesting.