Silence often means a child is thinking. Give them plenty of time to answer. Reinforce good behavior. Let your student know how proud you are of them. This will encourage them to try harder.
Children never forget.
If you promise them something, be prepared to keep the promise. Use positive comments that will make students feel good about themselves even when they are having difficulty. Avoid saying anything that will make students doubt themselves or their ability to learn. Do not be discouraged if you think little progress is being made. Your very presence and interest is helping your student to be successful.