You can avoid this from happening by getting the private key of the address holding the balance and import it as solo address, this time every time you send part of the Bitcoin of the existing balance, the excess will return back to the same address because it is the only address available in the imported wallet address.
It depends on the wallet that you're using, example is Electrum wallet, on the GUI, click on tools -> preferences -> transactions and uncheck 'use change addresses'.
Though this might compromise privacy but then you will always see the whole balance in the same address when using a blockchain explorer.
It is not necessary, wallet will always estimate the total amount of bitcoin you have on the addresses that your wallet generate.