Unit Name: Multiplicative Comparisons
Common Core State Standards:
4.OA.1 Interpret a multiplication equation as a comparison, e.g., interpret 35 = 5 × 7 as a statement that 35 is 5 times as many as 7 and 7 times as many as 5. Represent verbal statements of multiplicative comparisons as multiplication equations.
4.OA.2 Multiply or divide to solve word problems involving multiplicative comparison, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem, distinguishing multiplicative comparison from additive comparison.
• multiplicative comparisons
• mental computation
In this unit, students will apply their understanding of place value to help them explore multiple groups or division. Students will utilize their knowledge of base ten and groups of numbers within another number to help them compare quantities or numbers. Students will be asked to not only identify, but will need to verbalize which quantity is being multiplied and which quantity tells how many times it is multiplied. Students will need to illustrate comparative situations with various strategies listed below. In addition,students will need to translate the situation into an equation.
Students will build on their understanding of addition and subtraction by using place value strategies to make sense of the standard algorithms. They are expected to use a variety of models to support their reasoning about numbers.
• Comparison Bars
• Number Lines
o Comparing numbers using bar models
o See multiplication as a comparison using number sentences
o Compare numbers using additive and multiplicative comparisons
o Represent unknown numbers using symbols or letters
o Solve multiplicative comparison word problems by using bar models
o Solve multiplicative comparison word problems by using bar models to represent divison
o Solve multiplicative comparison word problems using multiplication or division
Mrs. Ana Rhyne
I teach 4th grade math and science at Weatherstone Elementary School. I graduated from Meredith College with a BA in Spanish and K-6 licensure.