7th Grade · Geometry
Scale Factor
7.G.A.1
Definition
The ratio of corresponding dimensions of two similar figures. Multiply original dimensions by the scale factor to find the new dimensions.
Teach it
Where it is taught, with guided notes, practice, homework, an exit ticket and an interactive Teacher Deck.
Examples
- New 12cm ÷ original 4cm = scale factor 3 (enlargement).
- Scale factor 1/2 means the new figure is half the original size — a reduction.
Key rule
Scale factor greater than 1 is enlargement; less than 1 is reduction.
Memory hook
Multiply by the scale factor to resize.