Multiplying Decimals 3 Act Task

Earlier this year, students built conceptual understanding of multiplication of whole numbers and decimals and multiplication of decimals by decimals. They used concrete models and grid paper to model the multiplication to find the product. The standard, MAFS.5.NBT.2.7, requires students to, “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.”

Many times, students can regurgitate the steps in “solving” a math problem yet, many students lack the skills to apply the learning to real life situations. Connecting Math to the real world is an integral part of learning and encourages retention of the skill. There are many opportunities for students to engage in real life math that encourages them to practice the skill of multiplying decimals.

Check out these videos from https://gfletchy.com/gassed/ where students can apply their understanding of multiplication of decimals to a real life situation.

How much will it cost to fill up the gas tank?

Show students this quick video and have them make predictions about the cost of filling the gas tank. Estimation is an underutilized skill that is beneficial to helping students decide on the reasonableness of their answer.

Show the tank capacity and price per gallon to the students and watch them solve! Note the strategies they use when solving for the cost to fill up the car.
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Once students arrive at their answer, show them the following video to discuss if their answer was reasonable.

For more 3 Act Tasks ideas, check out https://gfletchy.com/3-act-lessons/