Big Ideas:
Multiplying by a decimal number with a value less than one will result in a product that is smaller than the original number.
Each place value to the left is ten times greater than the one to the right.
This lesson builds on students' work with multiplying whole numbers and decimals. In this lesson students will use a variety of strategies to multiply decimal numbers and whole numbers. These strategies may include, but are not limited to, number-line diagram, partial products, repeated addition, and area models. In this task student are presented with a problem to solve and will show their solution using two different strategies. The mathematical concepts in this lesson build toward students’ future work with multiplying rational numbers and proportional reasoning in grades 6-8.
Vocabulary: multiplication, product, factor, commutative property, estimate, area model, partial products, decimal, decimal point, tenths, hundredths
Special Materials:
Number lines
Grid paper
White boards and markers
Base Ten Blocks
Money sets
Lesson plan