All the solutions provided in McGraw Hill Math Grade 3 Answer Key PDF Chapter 6 Lesson 2 Multiply by 2 will give you a clear idea of the concepts.
McGraw-Hill My Math Grade 3 Answer Key Chapter 6 Lesson 2 Multiply by 2
Math in My World
Example 1
The students in an art class are working on a project. How many students are there in the art class if there are 8 groups of 2?
Find 8 groups of 2.
Write 8 groups of 2 as 8 × 2.
One Way Use an array.
Draw an array with 8 rows and 2 columns.
Another Way Draw a picture.
Draw 8 equal groups of 2.
Write an addition sentence and multiplication sentence.
___ + ___ + ___ + ___ + ___ + ____ + ___ + ___ = ____ ___ × ___ = ____
So, 8 × 2 = ____. There are ____ students in the art class.
← You can write it vertically, also.
No matter which way you write a multiplication fact, you still read it the same way.
Answer:
The addition sentence and multiplication sentence is
2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 16.
So, 8 × 2 = 16.
There are 16 students in the art class.
Example 2
Seth rides his bike to the park Mondays, Wednesdays, and Fridays. It is 2 miles round-trip. How many miles does he ride for the three days? Write a multiplication sentence with a symbol for the unknown. Then, use a bar diagram to solve.
1. Model 2 miles a day as one part.
1 part = 2 miles
2. Since he rode the same amount for 3 days, model a total of 3 parts.
3. Write a multiplication sentence. __ days × ___ miles a day = ___ miles
So, 3 × 2 = ____
Seth rode ___ miles for the 3 days. The unknown is _____.
Answer:
Model 2 miles a day as one part.
1 part = 2 miles
Since he rode the same amount for 3 days, model a total of 3 parts.
Write a multiplication sentence.
3 days × 2 miles a day = 6 miles
So, 3 × 2 = 6
Seth rode 6 miles for the 3 days. The unknown is 6 miles.
Guided Practice
Write an addition sentence and a multiplication sentence for each.
Question 1.
4 groups of 2 is ____
2 + 2 + ____ + ____ = ____
4 × ___ = ____
Answer:
4 group of 2 is 8.
2 + 2 + 2 + 2 = 8.
4 x 2 = 8.
Question 2.
3 groups of 2 is ____
2 + 2 + ____ = ____
3 × ___ = ____
Answer:
3 group of 2 is 6.
2 + 2 + 2 = 6
3 x 2 = 6.
Talk Math
Describe two strategies you can use to remember the multiplication facts for 2.
Answer:
Multiplication fact is the product of two specific numbers. The order of numbers will change also the product does not change.
It is 1 x 2 = 2.
2 x 1 = 2.
Independent Practice
Write an addition sentence and a multiplication sentence for each.
Question 3.
Answer:
2 group of 2 is 4.
2 + 2 = 4.
2 x 2 = 4.
Question 4.
Answer:
6 group of 2 is 12.
2 + 2 + 2 + 2 + 2 + 2 = 12.
6 x 2 = 12.
Draw an array for each. Then write a multiplication sentence.
Question 5.
3 rows of 2
____ × ___ = ____
Answer:
Given that
3 rows of 2 is 6.
Multiply 3 with 2 then you get 6.
The array of 3 rows of 2 is
Question 6.
2 rows of 3
____ × ___ = ____
Answer:
Given that
2 rows of 3 is 6.
Multiply 2 with 3 then you get 6.
The array of 2 rows of 3 is
Question 7.
The arrays in Exercises 5 and 6 show the ____ Property.
Answer:
The arrays in Exercises 5 and 6 show the commutative Property.
Commutative property means the order in which we multiply numbers does not change the product.
Algebra Write a multiplication sentence with a symbol for the unknown. Then solve.
Question 8.
How many ears are on 4 dogs?
____ × ____ = 
There are ____ ears.
Answer:
1 dog has 2 ears.
4 dogs = 4 x 2 = 16.
Therefore there are 16 ears.
Question 9.
There are a total of 16 legs on 2 spiders. How many legs each?
____ × = ____
Each spider has ____ legs.
Answer:
Given that,
2 spiders has 16 legs
each spider has 16/2 = 8.
Therefore each spider has 8 legs.
Write a multiplication sentence.
Question 10.
Answer:
Given that,
There are 4 bicycles.
Each bicycles has 2 wheels.
The number of wheels for bicycles are 4 x 2 = 8.
Therefore the number of wheels are 8.
Question 11.
Answer:
Given that,
There are 2 coats.
Each coat has 5 buttons.
The total number of buttons are 5 x 2 = 10.
Therefore the number of buttons are 10.
Problem Solving
Mathematical PRACTICE 2 Use Algebra Write a multiplication sentence with a symbol for the unknown. Then solve.
Question 12.
How many sides are there altogether on two squares?
____ × 2 = 
There are ___ sides.
Answer:
Given that,
The number of squares are 2.
Each square has 4 sides.
4 x 2 = 8.
Therefore there are 8 sides.
Question 13.
How many gloves are there altogether if Ryder has 6 pairs of gloves?
____ × 2 =
Ryder has ____ gloves altogether
Answer:
Given that,
Ryder has 6 pairs of gloves.
1 pair of gloves has 2 gloves.
6 x 2 = 12.
Therefore Ryder has 12 gloves altogether.
Question 14.
Paige has 24 magazines in her magazine collection. Each month she adds 2 more magazines to her collection. How many magazines will she have in 3 months? Write two number sentences to show how to solve.
She will have ____ magazines.
Answer:
Given that,
Paige has 24 magazines in her magazine collection.
Each month she adds 2 more magazines to her collection.
The number of magazines in 3 months are 24 + 2 + 2 + 2 = 30.
The another is for 3 months the magazines are 3 x 2 = 6.
24 + 6 = 30.
Therefore the number of magazines are 30.
HOT Problems
Question 15.
Mathematical PRACTICE 4 Model Math Write a word problem a real-world situation in which a number is multiplied by 2.
Answer:
The word problem is Raju has 6 apples each apple cost is Rs 2. find the cost of 6 apples.
6 x 2 = 12.
Therefore the cost of 6 apples is Rs 12.
Question 16.
? Building on the Essential Question What do you notice about all of the products of 2? Use the multiplication table.
Answer:
Using the multiplication table.
All the products of 2 is the even numbers.
McGraw Hill My Math Grade 3 Chapter 6 Lesson 2 My Homework Answer Key
Practice
Write an addition sentence and a multiplication sentence.
Question 1.
3 groups of 2 is ____.
2 + ____ + ____ = ____
____ × 2 = ____
Answer:
3 groups of 2 is 6.
2 + 2 + 2 = 6.
3 x 2 = 6.
Multiply 3 with 2 then you get 6.
Question 2.
4 groups of 2 is ____.
2 + ____ + ____ + ___ = ____
____ × 2 = ____
Answer:
4 groups of 2 is 8.
2 + 2 + 2 + 2 = 8.
4 x 2 = 8.
Multiply 4 with 2 then you get 8.
Draw an array for each. Then write a multiplication sentence.
Question 3.
7 rows of 2
____ × ____ = ____
Answer:
Given that,
7 rows of 2.
7 x 2 = 14.
The array of 7 rows of 2 is
Question 4.
2 rows of 5
____ × ____ = ____
Answer:
Given that,
2 rows of 5
2 x 5 = 10.
Multiply 2 with 5 then you get 10.
The array of 2 rows of 5 is
Problem Solving
Mathematical PRACTICE 2 Algebra Write a multiplication sentence with a symbol for the unknown. Then solve.
Question 5.
Franklin’s father gave him and his sister $8 each to spend at the movies. How much money did Franklin’s father give the children altogether?
Answer:
Given that,
Franklin’s father gave him and his sister $8 each to spend at the movies.
Therefore Franklin’s father give the children altogether is $8 + $8 = $16.
Question 6.
There are 7 people in the Watson family. They all keep their gloves in 1 box in the closet. If each person has a pair of gloves, how many gloves are in the box?
Answer:
Given that,
There are 7 people in the Watson family.
Each person has a pair of gloves. It has it has 2 gloves.
The number of gloves in box is 7 x 2 = 14.
Therefore there are 14 gloves in the box.
Vocabulary Check
Question 7.
Write or draw the meaning of a bar diagram.
Answer:
The meaning of the bar graph is it has vertical and horizontal bars whose bars length is proportional to amount.
Draw the bar diagram for the number of students in the math’s class.
Test Practice
Question 8.
James is jumping on a pogo stick. He is counting by twos. If he counts to 12, how many jumps has he made?
A. 2 jumps
B. 4 jumps
C. 6 jumps
D. 10 jumps
Answer:
Given that,
James is jumping on a pogo stick. He is counting by twos.
If he counts to 12 then the number of jumps he made is 12/2 = 6 jumps.
Option C is the correct answer.