## Big Ideas Math Book 2nd Grade Answer Key Chapter 1 Numbers and Arrays

Apply the math to real-time examples by learning the tricks using Big Ideas Math Answers Grade 2 Chapter 1 Numbers and Arrays. The quick way of solving math problems will help the students to save time. So, we suggest the students practice more questions which helps them to score good marks in the exams. If you want the best way of learning then you must use Big Ideas Math Grade 2 Chapter 1 Numbers and Arrays Answer Key.

Vocabulary

Lesson 1: Even and Odd Numbers

Lesson 2: Model Even and Odd Numbers

Lesson 3: Equal Groups

Lesson 4: Use Arrays

Lesson 5: Make Arrays

### Numbers and Arrays Vocabulary

Organize It

Use the review words to complete the graphic organizer.

‘+’ is the mathematical symbol used to represent the notion of positive as well as the operation of addition.

Define It

Use your vocabulary cards to identify the word.

Question 1.

Question 2.

Question 3.

Chapter 1 Vocabulary Cards

### Lesson 1.1 Even and Odd Numbers

Explore and Grow

Use linking cubes to model each story.
There are 6 students in the gym. Does each student have a partner?
There are 5 students in the library. Does each student have a partner?

Think and Grow

Show and Grow

Question 1.

Explanation: There are 6 parts, An even number can be shown as 2 equal parts.

Question 2.

Explanation: There are 9 parts, An odd number cannot be shown as 2 equal parts.

Color cubes to show the number. Circle even or odd.

Question 3.

Explanation: 11 is odd number and cannot be shown as 2 equal parts.

Question 4.

Explanation: 16 is even number and can be shown as 2 equal parts.

Apply and Grow: Practice

Color cubes to show the number. Circle even or odd.

Question 5.

Explanation: 13 is odd number and cannot be shown as 2 equal parts.

Question 6.

Explanation: 10 is even number and can be shown as 2 equal parts.

Is the number even or odd?

Question 7.

Explanation: 1 is odd number and cannot be shown as 2 equal parts.

Question 8.

Explanation: 4 is even number and can be shown as 2 equal parts.

Question 9.

Explanation: 18 is even number and can be shown as 2 equal parts.

Question 10.

Explanation: 17 is odd number and cannot be shown as 2 equal parts.

Question 11.

Explanation: 19 is odd number and cannot be shown as 2 equal parts.

Question 12.

Explanation: 20 is even number and can be shown as 2 equal parts.

Question 13.
Number Sense
Circle even or odd to describe each group. Then write each number in the correct group.

Think and Grow: Modeling Real Life

There is an even number of students in your class. There are more than 16 but fewer than 20 students. How many students are in your class?

Explanation: Between 16 and 20, Even number is 18.

Show how you know:

Show and Grow

Question 14.
There is an odd number of cows in a ﬁeld. There are more than 13 but fewer than 17 cows. How many cows are in the ﬁeld?

Explanation: Between 13 and 17, Odd number is 15.

Question 15.
There are 14 geese on a farm. There are 2 more chickens than geese. Is there an even or odd number of chickens?

Explanation: There are total 16 Chickens on a farm, which is Even number.

### Even and Odd Numbers Home & Practice 1.1

Question 1.

Explanation: Total 11 parts, which cannot be shown as 2 equal parts.

Question 2.

Explanation: Total 10 parts, which can be shown as 2 equal parts.

Color cubes to show the number. Circle even or Odd

Question 3.

Explanation: 9 is Odd number which cannot be shown in 2 equal parts.

Question 4.

Explanation: 14 is Even number which can be shown in 2 equal parts.

Question 5.

Explanation: 18 is Even number which can be shown in 2 equal parts.

Question 6.

Explanation: 15 is Odd number which cannot be shown in 2 equal parts.

Is the number even or odd?

Question 7.

Explanation: 2 is Even number which can be shown in 2 equal parts.

Question 8.

Explanation: 5 is Odd number which cannot be shown in 2 equal parts.

Review & Refresh

Question 9.
DIG DEEPER!
You break apart a linking cube train to make two equal parts. There is 1 cube left over. Is the number of cubes even or odd? Explain.

Explanation: There are 5 parts in cube train, when it is broken in 2 equal parts then there is 1 cube left (2+2+1) which is Odd number.

Question 10.
Modeling Real Life
There is an even number of eggs in a nest. There are more than 10 but fewer than 14 eggs. How many eggs are in the nest?

Explanation: 12 is even number and also between 10 and 14, 12 is the only even number.

Question 11.
Modeling Real Life
You have 6 green crayons. You have 1 more blue crayon than green crayons. Do you have an even or an odd number of blue crayons?

Explanation:  Total 7 blue crayon which is Odd number so it cannot be shown in 2 equal parts.

Review & Refresh

Question 12.
6 + 6 = ___
Explanation: 12 is Even number which can be shown in 2 equal parts.

Question 13.
9 + 9 = ___
Explanation: 18 is Even number which can be shown in 2 equal parts.

Question 14.
7 + 7 = ___
Explanation: 14 is Even number which can be shown in 2 equal parts.

Question 15.
8 + 8 = ___
Explanation: 16 is Even number which can be shown in 2 equal parts.

### Lesson 1.2 Model Even and Odd Numbers

Explore and Grow

Use linking cubes to model each sum. Is the sum even or odd?

Explanation: 4+4=8, 8 is Even number which can be shown in 2 equal parts.

Explanation: 5+4=9, 9 is Odd number which cannot be shown in 2 equal parts.

Show and Grow

Question 1.

Explanation: 7=4+3, Odd number

Question 2.

Explanation: 10=5+5, Even number

Question 3.

Explanation: 14=7+7, Even number

Question 4.

Explanation: 17=9+8, Odd number

Question 5.

Explanation: 18=9+9, Even number

Question 6.

Explanation: 13=7+6, Odd number

Question 7.

Explanation: 15=8+7, Odd number

Question 8.

Explanation: 20=10+10, Even number

Question 9.
YOU BE THE TEACHER
Descartes uses doubles plus 1 to model an odd number. Is he correct? Explain.

Explanation: 3+4=7, Odd number which cannot be shown as 2 equal parts.

Question 10.
You do 6 sit-ups on Saturday and 7 on Sunday. Do you do an even or odd number of sit-ups in all?

Explanation: 6+7=13, It is an Odd number

Think and Grow: Modeling Real Life

There is an even number of marbles in one bag and an odd number of marbles in another bag. Is there an even or an odd number of marbles in all?

Which equation could match the story?

There is an ___ number of marbles in all.
Explanation: 8+7=15, 8 is even and 7 is odd number, in total 15 is Odd number of marbles.

Show and Grow

Question 11.
Two buckets each have an odd number of seashells. Is there an even or an odd number of seashells in all?

Which equation could match the story?

There is an __ number of seashells in all.
Explanation: 9+5=14, 9 and 5 are odd numbers which in total 14 is Even number.

Question 12.
DIG DEEPER!
You have an odd number of ﬂowers. You and your friend have an even number of ﬂowers in all. Does your friend have an even or an odd number of ﬂowers?

Your friend has an ___ number of ﬂowers.
Explanation: Friend has only even number of flowers.

### Model Even and Odd Numbers Homework & Practice 1.2

Question 1.

Explanation: 8=4+4, Even number

Question 2.

Explanation: 17=9+8, Odd number

Question 3.

Explanation: 9=5+4, Odd number

Question 4.

Explanation: 16=8+8, Even number

Question 5.
Reasoning
Fill in the blanks using even or odd.
The sum of two even numbers is ___.
The sum of two odd numbers is ___.
The sum of an even number and an odd number is __.

Question 6.
You do 10 jumping jacks on Saturday and 10 on Sunday. Do you do an even or odd number of jumping jacks in all?

Explanation: 10+10=20, which is Even number.

Question 7.
Modeling Real Life
You and your friend each have an even number of googly eyes. Do you and your friend have an even or an odd number of googly eyes in all?

Which equation could match the story?

You have an __ number of googly eyes in all.
Explanation: 4 and 6 are Even numbers. So totally 10 googly eyes which is even number.

Question 8.
DIG DEEPER!
You hop an even number of times. You and your friend hop an odd number of times in all. Does your friend hop an even or an odd number of times?
Your friend hops an ___ number of times.
Explanation: you hop an even and overall odd number, so your friend has odd number of times.

Review & Refresh

Circle the shape that shows equal shares.

Question 9.

Question 10.

### Lesson 1.3 Equal Groups

Explore and Grow

Circle groups of two oranges. Complete the sentence.

Answer: 4 groups of 2 is 8.

Show and Grow

Question 1.

5+5=10

Question 2.

2+2+2=6

Question 3.
Circle groups of 3. Write a repeated addition equation.

5+5+5+5+5=25

Apply and Grow: Practice

Question 4.
Circle groups of 5. Write a repeated addition equation.

5+5=15

Question 5.
Circle groups of 4. Write a repeated addition equation.

Question 6.
YOU BE THE TEACHER
Newton says he can circle 5 equal groups. Is he correct? Explain.

Yes he is correct. Newton can circle 3 groups of 5 parts. So, 3+3+3+3+3=15

Think and Grow: Modeling Real Life

You have 3 boxes. There are 5 pencils in each box. How many pencils are there in all?

Model:

Answer: 15 pencils in total. 5+5+5=15.

Show and Grow

Question 7.
You have 5 bags. There are 4 notebooks in each bag. How many notebooks are there in all?

Answer: 20 notebooks in total. 5+5+5+5=20.

Question 8.
DIG DEEPER!
There are 4 boxes. Each box has the same number of glue sticks. There are 16 in all. How many glue sticks are in each box?

Answer: There are 4 glue sticks in each box.

Question 9.
Explain how you solved Exercises 7 and 8. What did you do differently?
_______________________________________
_______________________________________

### Equal Groups Homework & Practice 1.3

Question 1.

3+3=6

Question 2.

4+4+4=12

Question 3.
Circle groups of 2. Write a repeated addition equation.

Question 4.
Structure
Show two different ways to put the buttons in equal groups.
One Way:

Another Way:

Question 5.
Modeling Real Life
You have 3 jars of paint brushes.There are 6 paint brushes in each jar. How many paint brushes are there in all?

Explanation: 6+6+6=18
Review & Refresh

Question 6.

How many students chose baseball? ___

Which sport is the most favorite?

### Lesson 1.4 Use Arrays

Explore and Grow

How many equal groups are there? Write an addition equation to tell how many cars there are in all.

Number of equal groups: ___
3+3=6

Show and Grow

Question 1.

4+4=8

Question 2.

4+4+4=12

Question 3.

4+4+4+4=16

Apply and Grow: Practice

Question 4.

5+5=10

Question 5.

3+3+3=9

Question 6.

5+5+5=15

Question 7.

5+5+5+5=20

Question 8.
Logic
Which arrays show the same number of circles?

Answer: Red and Blue circles show the same number.

Think and Grow: Modeling Real Life

The arrays show the desks in two classrooms. Which classroom has more desks?

Classroom A: 5+5+5+5+5=25
Classroom B: 7+7+7+7=28
Answer: Classroom B has more number of desks.

Show and Grow

Question 9.
The arrays show gardens of green and yellow pepper plants. Are there more green pepper plants or yellow pepper plants?

Explanation: There are 15 Green pepper plants and 12 Yellow pepper plants.

### Use Arrays Homework & Practice 1.4

Question 1.

2+2+2=6

Question 2.

2+2=4

Question 3.

1+1+1+1=4

Question 4.

6+6+6= 18

Question 5.
Number Sense
Use the array to complete the equation.

Question 6.
Modeling Real Life
The arrays show toy cars. Are there more orange cars or blue cars?

Explanation: There are 16 orange cars and 15 blue cars.

Question 7.
DIG DEEPER!
The arrays show a sheet of stickers separated into two pieces. How many rows and columns of stickers did the sheet have before it was separated?

Answer: 5 rows and 5 columns

Review & Refresh

Question 8.

8 vertices
12 edges

Question 9.

0  vertices
0 edges

### Lesson 1.5 Make Arrays

Explore and Grow

Use counters to model the story. Write an addition equation to match.

There are 4 rows of students. There are 3 students in each row. How many students are there in all?

Explanation: 3+3+3+3=12 students.

Show and Grow

Question 1.
A photo album has 3 rows of photos. There are 2 photos in each row. How many photos are there in all?

Explanation: 2+2+2=6

Question 2.
You have 4 rows of stickers. There are 5 stickers in each row. How many stickers do you have in all?

Explanation: 5+5+5+5=20

Apply and Grow: Practice

Question 3.
An ice cube tray has 5 rows. There are 2 ice cubes in each row. How many ice cubes are there in all?

Explanation: 2+2+2+2+2=10

Question 4.
A bookcase has 3 shelves. There are 5 stuffed animals on each shelf. How many stuffed animals are there in all?

Explanation: 5+5+5=15 stuffed animals

Question 5.
A closet has 4 shelves. There are 2 games on each shelf. How many games are there in all?

Explanation: 2+2+2+2=8

Question 6.
Structure
Make an array to match the equation.
5 + 5 + 5 + 5 = 20

Think and Grow: Modeling Real Life

A marching band has 3 equal rows of drummers. There are 15 drummers in all. How many drummers are in each row?

Model:

Explanation: 5+5+5=15

Show and Grow

Question 7.
A quilt has 4 equal rows of patches. There are 24 patches in all. How many patches are in each row?

Explanation: 6+6+6+6=24

Question 8.
A building has 3 equal rows of windows. There are 18 windows in all. How many columns are there?

Explanation: 3+3+3+3+3+3=18

### Make Arrays Homework & Practice 1.5

Question 1.
A parking lot has 3 rows. There are 5 parking spots in each row. How many parking spots are there in all?

Explanation: 5+5+5=15

Question 2.
A bookcase has 4 shelves. There are 3 books on each shelf. How many books are there in all?

Explanation: 3+3+3+3=12

Question 3.
Reasoning
Newton has 10 tokens. Which equations can Newton use to make an array with his tokens?

Question 4.
Modeling Real Life
A theater has 4 equal rows of seats. There are 16 seats in all. How many seats are in each row?

Explanation: 4+4+4+4=16

Question 5.
Modeling Real Life
A chorus has 5 equal rows of singers. There are 30 singers in all. How many singers are in each row?

Explanation: 6+6+6+6+6=30

Review & Refresh

Question 6.
There are 9 lions in all. How many lions are in the den?

Answer: 0 lions are in den.
Explanation: All 9 lions are outside the den. Therefore, 0 lions are in the den.

### Numbers and Arrays Performance Task

Question 1.
Your art supplies are packaged in boxes as described below.

a. What do you have the most of ?

Explanation: Colored Pencils= 5+5+5=15
Markers= 7+7=14
Crayons= 4+4+4+4=16
Crayons are more than Colored Pencils and Markers.
b. Do you have an even or an odd number of markers?

Question 2.
a. You have 5 equal rows of paint bottles. You have 20 paint bottles in all. How many paint bottles are in each row?

Answer: 4 paint bottles are in each row.
b. You add another row of paint bottles. How many paint bottles do you have now?
c. Describe another way to arrange the paint bottles you have now.

### Numbers and Arrays Activity

Array Flip and Find

To Play: Place the Array Flip and Find Cards face down in the boxes. Take turns ﬂipping two cards. If your cards show the same total, keep the cards. If your cards show different totals, ﬂip the cards back over. Play until all matches are made.

### Numbers and Arrays Chapter Practice

1.1 Even and Odd Numbers

Question 1.

Explanation: 5 cube part

Question 2.

Explanation: 14 cube part

Color cubes to show the number. Circle even or odd.

Question 3.

Question 4.

Question 5.
Modeling Real Life
You see an odd number of boats. There are more than 15 but fewer than 19 boats. How many boats do you see?

Show how you know:

Explanation: Between 15 and 19 there is Odd number 17.

1.2 Model Even and Odd Numbers

Question 6.

Question 7.

Question 8.

Question 9.

1.3 Equal Groups

Question 10.

Question 11.
Circle groups of 3. Write a repeated addition equation.

Question 12.
Structure
Show two different ways to put the balls in equal groups.
One Way:

Another Way:

1.4 Use Arrays

Question 13.

Question 14.

Question 15.

Question 16.

1.5 Make Arrays

Question 17.
A cupboard has 4 shelves. There are 3 glasses on each shelf. How many glasses are there in all?

Question 18.
A bingo card has 5 rows. There are 5 squares in each row. How many squares are there in all?