This is 7 levels of carefully-designed scientific notation practice problems. It's a great review/practice activity.
Level A - Converting from standard form to scientific notation
Level B - Converting from scientific notation to standard form
Level C - Mix of A and B
Level D - Adding and subtracting in scientific notation.
Level E - Multiplying and dividing in scientific notation
Level F - Word problems
Level G - More word problems
Level H - Challenge
I printed the levels on a variety of colored paper and spread them out on a desk. All students started with level A and moved through the levels at their own pace.I let students who breezed through levels A and B skip level C. As students completed each level they would come to me to get their work checked before picking up the next level. Students really enjoyed completing the levels and it was easy to send struggling students to more proficient students for quick tutoring sessions.