6th Grade Common Core Math Standard: Ratio & Proportional Relationships, A.3.B:

“Solve unit rate problems including those involving unit pricing and constant speed. For example, if it took 7 hours to mow 4 lawns, then at that rate, how many lawns could be mowed in 35 hours? At what rate were lawns being mowed?”

5th Grade Common Core Math Standard: Numbers & Operations in Base Ten, B.7:

“Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.”