Reducing fractions is another skill involved in just about any of the fraction operations. The fraction worksheets on this page introduce reducing gradually by providing problems with increasingly more difficult denominators, and only gradually introducing mixed numbers and improper fractions.
If you make your own, you can just draw three circles on a page and then 2-5 triangles on a page, and ask the child to match each circle with a triangle by drawing a line from shape to shape. Vary the shapes and the amounts. Sometimes the amounts should be equal, sometimes not.