Get some addition practice while reading picture books together. There are a ton of great picture books that have overt and hidden addition facts and practice, but you can turn any book into a lesson in addition. If you read a page with a picture of a forest, you might say to your child, "I see three trees and four flowers. How many plants are there all together?" You can add characters, shapes, items, or anything in multiples.
When adding fractions without a common denominator, it is necessary to find a common denominator before adding the numerators. Find two equivalent fractions by determining the least common multiple of the two denominators and using that as the denominator for both fractions.