First, I show how to multiply a number by ten, there is a shortcut: just tag a zero to the number. For example, 10 x 56 is 56 and a zero tagged... 560. Then we look at a rectangle and its area...and from there, go to study multiplications such as 3 x 40 or 7 x 90. For these there is a shortcut, too! For example, 7 x 90 equals 7 x 9 x 10, and in that, we can multiply 7 x 9 = 63 first, so the problem becomes 63 x 10 which equals 630.
Lastly there is a puzzle to solve!
Math Mammoth Grade 3 curriculum
https://www.mathmammoth.com/complete/grade_3
Online practice for multiplying numbers with zeros
https://www.mathmammoth.com/practice/multiply-with-zeros