Multiplying Decimals Model

Grade Level(s): 5^th grade – 6^th Grade

Content Area:                                                                        Process Area:

Numbers and Operations                                           Problem-Solving

Algebra                                                           Reasoning and Proof

Geometry                                                                    Communication

Measurement                                                             Representation

Data Analysis, Statistics, and Probability                    Connections

Common Core Standards:

CCSS.MATH.CONTENT.5.NBT.B.5: Fluently multiply multi-digit whole numbers using the standard algorithm

Targeted Needs of Student:

Multiplying decimals that have one digit, understanding that decimals are fractions written differently, representing abstract concepts in a visual way, learning how to move the decimal to the appropriate place.

Goal:

Visually representing how to multiply decimals using a 10 by 10 grid.

Materials Needed:

1. Large chart paper
2. Two different colored markers to shade
3. 10 by 10 grid

Explanation/Summary:

Teacher will model this way of understanding how to multiply decimals. This only works with one digit decimals (such as .4, .5, etc.) Using 10 by 10 grids, shade in the amount of rows of your first number you are multiplying. Then shade in the amount of columns (make sure they intersect) of your second number you are multiplying. Then count the amount of units that have been overlapped by the two shaded areas. This number is your answer. For instance if you have .3 x .4 (see model below) then you would shade three columns vertically and four rows horizontally and the amount of units that have been overlapped by both numbers is 12. Your answer is .3 x .4 = .12.

 

Resource:

www.onestopteachershop.com