Imagine Math for additional practice. This program is designed to work at your child's best level for learning. Here is the link to the site. https://lms.thinkthroughmath.com/users/sign_in
ABCya is a site which offers free educational computer games and mobile apps for kids, where engaging learning activities are available. https://www.abcya.com/
CommonLit.org might be my new favorite find. It offers leveled texts, each of which are followed with comprehension questions and links to other material of the same nature. https://www.commonlit.org/