Multiplication as scaling / resizing (5th grade math)
I use the visual model of scaling a stick to explain how multiplication works as a scaling process. If the factor we multiply by is more than 1, the stick gets longer, and if it is less than 1, it gets shorter.
Using this concept, we compare expressions that involve a fraction times another number. Then, we solve some fraction multiplication problems using the concept of scaling (and not the shortcut).
Lastly, I solve two word problems (scaling an image and doing a recipe 1 ½ times).
See also
Math Mammoth Grade 5 curriculum