Due to the fact that the services of 3G Internet call cell operators, then a balance check should be carried out using the proposed means. One of the easiest ways is to use your personal account on the operator's website, for which you must enter the number of the SIM card installed in the tablet. When using the Megaphone, you can just go to his website using a tablet and at the top of the screen indicates the balance.
Another common method is to use a special application widgets, for example piBalance, which you can download from play market or other source. This program displays the device balance for the operator. The use of such widgets is very useful because it does not require any additional actions. However, some programs may not work with the part of the operators, the most common problem is with Beeline.
Also, any operator has a service that allows you to check the balance on SIM-cards of family and friends. MegaFon and Beeline, for example, it is called a "Balance sheet Close", and MTS – "the balance of the Other." It can be connected to your cell phone number and find out the cash balance on the SIM card of the tablet.
If none of these methods is not available, you can simply remove the SIM card from the modem to the tablet and insert it in your cell phone, then send USSD request to check for available funds. For MTS and MegaFon you can send USSD by dialing *100#, and Beeline *102#. After that, the phone will get a SMS with balance. Then the SIM card can be returned to the tablet.