Connecting iPad and Tablet to Wireless

First, check how many other devices are connected -the router may be struggling with the number of devices connected. Try disconnecting the iPhone and connecting the iPad. If it connects then disconnect the iPad and try to connect the android tablet. If this succeeds and you can't connect a second concurrent device, you may have a faulty wireless router.
Then try resetting the devices

iPad:
Settings>generat>reset>reset network settings

Android:
try setting a static ip  or reset to factory default after backing up

What is the make and model of the router?

We have 2 different routers - one is an Actiontec and the other is a Linksys.

so it happens on both routers?

Just as an experiment, take your tablets to somewhere there's free wifi & see if they connect. By doing this, you are eliminating the tablets as the potential source of the problem. If they both connect, your problem lies with your own wifi network. I'm not sure why you've got two routers as each wireless router can theoretically connect 255 different devices (but practically 32 is usual), unless you have them bridged and are operating over a large area. I would connect only 1 wireless router to your modem and then see what happens.

And what are the model numbers?

I will get the model numbers tonight when I go by the school. I don't know if they have given up on the iPad but we have the same issue with Chromebooks.
The tablets do connect on free wifi.

So sounds like the configuration of the wireless network. Unless you're a network specialist, I'd suggest getting a specialist in to reconfigure & troubleshoot

So what would be the configuration problem? I can connect a standard Windows wireless device but not an iPad or Chromebook. Is is the security or something else?

I keep asking what the model numbers are as that may be the key and will now add that it would greatly help to ALSO know the security configuration?

I will get the model #s tonight when I go by the school.

We have 3 different routers in 3 different parts o the school. They all have a unique SSID and DHCP has been turned off in all of them. They are -

Netgear WNR834B Ver. 3

Actiontec MI424-WR Rev. D

Linksys WRT120N

Is there a router that is recommended for connection to iPads?

Tried reconfiguring the Netgear WNR834B Ver. 3 but I keep getting an error that the LAN and WAN subnets are conflicting. I know I need to set this up with DHCP turned off and I had it working before but now I can get it back to where it was and can't seem to resolve that error so I can see if changing the security solves the problem.

No solution was ever found for this issue.

I'm sorry. I never got notification of your last posting....
Whenever I setup a slave router, I do not use the WAN port at all.  I first set it up at a fixed ip address, turn off the DHCP, and plug the network cable into one of the LAN ports.  Is that how you have it setup?

Yes. We have several throughout the two school buildings and the WAN ports are not used.

According to the Netgear forums, that message is due to the DNS server settings on the WAN port.  Can you check one that still works?