Grade 3
Use any of these links to practice your skills:
http://www.mathk8.nelson.com/math3/studentcentre/studtryout.html#ch12 - Choose from lessons 1, 2, or 3.
https://ca.ixl.com/math/grade-3 - Choose from sections E or F for multiplication (only go up to 7x7). Choose from sections I or J for division (only go up to 49/7). Choose from section Y for fractions learning.
Grade 4
Use any of these links to practice your skills:
http://www.math4.nelson.com/studentcentre/studtryout.html#ch12 - Use lessons 1 (Fractions of an Area), 3 (Fractions of a Set), 4 (Decimal Tenths), 5 (Decimal Tenths Greater Than One), 6 (Adding Decimal Tenths), 7 (Subtracting Decimal Tenths).
https://ca.ixl.com/math/grade-4 - Choose from sections R: Understand Fractions, S: Equivalent Fractions, T: Compare and Order Fractions, U: Decimals, V: Add and Subtract Decimals.