How would I record this general journal entry for aje

An inventory count shows 400$ of cleaning supplies on hand at march 31

It looks like an adjusting entry to me. You have to know what the account balance is, or you have to be able to compute this amount.

For example your cleaning account says you have $500 worth of cleaning supplies onhand, but your inventory count is actually $400 you have do an adjusting entry to bring your account balance into agreement with your inventory balance.

Your adjusting entry will be:
Debit Cleaning Supplies Expense for 100
Credit Cleaning Supplies for 100

Now your Cleaning Supplies account balance is $400 ($500 account balance - $100 worth of cleaning supplies used).