How many of the thirteen states needed to approve a law before it could be passed, under the articles of confederation?

At least 9 out of the 13 states needed to approve a law before it could be pass from the congress.

Explanation:

All states agree to send the delegates to Congress to vote on law or proposal.Congress could pass the laws although at least 9 out of the 13 states had to approve the law before it could pass and become the law.Congress could not levy or collect taxes, the state has control over the taxes.Congress had the right to declare war, appoint military officers and can control and create coin money.