Like Terms Invaders  
Common Core Math Alignment: 6.EE.3. Apply the properties of operations to generate equivalent expressions.
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50% (320 x 350) 
75% (480 x 525) 
100% (640 x 700) 
150% (960 x 1050) 
200% (1280 x 1400) 
300% (1920 x 2100) 