Grade Level: Elementary/Intermediate
My Unit Plan: Math
Title: Mental Math: Multiplication Patterns of Whole Numbers using 10, 100, and 1000
Grade Level: 5th
Overview: By 5th grade, students have explored basic multiplication concepts and operations. Now they are ready to learn how to multiply with zeros in the product. Learning how to successfully use mental math for multiplying by 10, 100, and 1000 is an important step to becoming a competent mental mathematician!
Assessment: Ask students to demonstrate their mental math skills by asking them to multiply basic facts using zeros.
My Best Lesson(s) for This Unit
Lesson Plan Title: Chalk it up to Mental Math!
Grade Level: 5th grade
Duration: 30 minutes
Student Goal: The student will demonstrate skills learned to perform mental math computations using basic facts and patterns of zeros.
Student Objectives: The student will exhibit increased confidence while exercising mental math skills when multiplying whole numbers.
List Materials: Individual chalk boards (black construction paper may be substituted); cloth or sponge erasers; chalk; Math: Math Functions (PDF) -- a content sample from the Scholastic Math Notebook by Mead, available early summer 2004 in the Teacher Store.
Set Up and Prepare: Make a quick assessment of prior knowledge by asking students to copy and find the products: 5x4=____, 50x4=___, 500x4=___, and 5000x4=___. Ask students to express how these problems are alike (basic facts) and if they recognize a pattern of any kind. Encourage students to express other examples of this same concept.
Directions: Share with students how math concepts, including multiplying with zeros, can be useful when learning about other subjects like science, reading, and social studies. Read the following word problems with students. Have students respond by exercising their mental math skills and recording answers on individual chalk boards. Discuss information, compare answers.
PART I: Remind students to isolate the basic fact, multiply, and then write zeros, depending on how many are in the factors. Chalk boards cleaned? Then you're ready to exercise your mental math skills with these fun word problems!
Step 1: Did you know that the Bottlenose dolphin can swim 16 kilometers an hour? How many kilometers could be traveled if he swam 10, 100, and 1000 hours? Imagine the distance traveled over the course of 10,000 hours. Answers: 160 hrs.; 1,600 hrs.; 16,000 hrs.;160,000 hrs.
Step 2: It's amazing that a giant octopus can weigh up to 125 pounds! If groups of 10, 100, and 1000 of these incredible sea creatures became entangled in a ship's fishnet, how much would each group weigh? Answers: 1,250 lbs.; 12,500 lbs.; 125,000 lbs.
Step 3: It's been said that Andrew Jackson was the first U. S. President to ride as a passenger on a train. American trains, invented around the year 1825, moved at a speed of 60 miles per hour. If President Jackson rode for 20 hours in a week, how many miles did he travel? If he rode for a total of 200 hours in a year, how far did he travel? If he rode for a total of 2000 hours over the period of his lifetime, how many miles did he travel? Answers: 1,200 miles; 12,000 miles; 120,000 miles
Step 4: The length of a day on Earth is about 24 hours. How many hours have passed after 40, 400, and 4000 days? Answers: 960 hrs; 9,600 hrs; 96,000 hrs.
Assess Students: Check understanding by giving students opportunities to create their own word problem by substituting new numbers in one of the above word problems, or let them create an original word problem.
Lesson Extension: Extend learning the rule for multiplying zeros by having students write or recite from memory: The final product is the product of the basic fact plus one zero for tens, two zeros for hundreds, and three zeros for thousands.
For more fun challenges:
Time the students as they write or speak.
Break the rule into word cards. Time individuals or teams as they work to arrange the words back into the rule sentence.
Evaluate Lesson: After students demonstrate mastery of this math concept, prepare five to ten word problems for them to independently solve. Check, correct, and reteach, if needed.
ORGANIZATIONAL TIPS FOR ENCOURAGING SUCCESS IN MATH CLASS:
Fourth, fifth, and sixth graders are just now beginning to develop their own classroom organizational skills, and for most, there is usually room for improvement in this important area of learning. Encourage students to prepare for success in math class by using the Scholastic Math Notebook by Mead math notebook (color-coded blue). Help students become more successful in your math class by using these simple ideas for the classroom:
Some of the resources on this page are in PDF format. To download them, you will need Adobe Acrobat Reader Software.
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