Refer to our Texas Go Math Grade 1 Answer Key Pdf to score good marks in the exams. Test yourself by practicing the problems from Texas Go Math Grade 1 Lesson 13.4 Answer Key Unknown Numbers.
Texas Go Math Grade 1 Lesson 13.4 Answer Key Unknown Numbers
Explore
Listen to the problem. Use 
to show the story. Draw to show your work.
Answer:
FOR THE TEACHER • Read the problem. Calvin has 7 toy cars that are red. He has some blue toy cars. He has 10 toy cars. How many blue toy cars does Calvin have?
Answer:
Calvin has red toy cars = 7
Total number of toy cars are 10
He has some blue cars.
Total number of blue cars = 10 – 7 = 3
Math Talk
Mathematical Processes
How many toy cars are blue? Explain how you got your answer.
Answer:
Model and Draw
What are the unknown numbers?
Use what you know about related facts to find the unknown parts.
Answer:
The unknown parts is 3.
Share and Show
Use to find the unknown numbers. Write the numbers.
Question 1.
8 + __________ = 15
15 – 8 = __________
Answer:
8 + 7 = 15
15 – 8 = 7
Question 2.
13 = 9 + __________
__________ = 13 – 9
Answer:
13 = 9 + 4
4 = 13 – 9
Question 3.
5 + __________ = 14
14 – 5 = __________
Answer:
5 + 9 = 14
14 – 5 = 9
Question 4.
14 = 6 + __________
__________ = 14 – 6
Answer:
14 = 6 + 8
8 = 14 – 6
Question 5.
9 + __________ = 16
16 – 9 = __________
Answer:
9 + 7 = 16
16 – 9 = 7
Question 6.
17 = 8 + __________
__________ = 17 – 8
Answer:
17 = 8 + 9
9 = 17 – 8
Problem Solving
Write the unknown numbers. Use if you need to.
Question 7.
7 + __________ = 15
15 – 7 = __________
Answer:
7 + 8 = 15
15 – 7 = 8
Question 8.
5 + __________ = 11
11 – 5 = __________
Answer:
5 + 6 = 11
11 – 5 = 6
Question 9.
__________ + 10 = 20
20 – 10 = __________
Answer:
10 + 10 = 20
20 – 10 = 10
Question 10
__________ + 9 = 16
16 – 9 = __________
Answer:
7 + 9 = 16
16 – 9 = 7
Question 11.
H.O.T. Solve. Rick has 10 party hats. He needs l hats for his party. How many more party hats does Rick need?
_________ party hats
Answer:
Question 12.
H.O.T. Multi-Step Solve. Use if you need to.
There were 15 children at the park. Some children went home. Then 4 more children came to the park. Now there are 13 children at the park. How many children went home?
__________ children
Answer:
Total number of children at the park = 15
More children came to park = 4
Total number of children came to park = 19
Now children at the park = 13
Children went to home = 19 – 13 = 6
Daily Assessment Task
Use . Choose the correct answer.
Question 13.
Analyze 14 cars are at the starting line. 10 cars cross the finish line. How many cars did not cross the finish line?
10 + ________ = 14
(A) 4
(B) 9
(C) 5
Answer:
Cars at the starting line = 14.
Cars cross the finish line = 10
The cars did not cross the line are 14 – 10 = 4
Option A is the correct answer.
Question 14.
Nick has 3 blue cubes in his hand. The cubes on his desk are yellow. He has 12 cubes. How many yellow cubes does Nick have?
3 + _________ = 12
12 – __________ = 3
(A) 6
(B) 9
(C) 4
Answer:
Total number of cubes near Nick = 12
Nick has blue cubes in his hand = 3
The remaining cubes are yellow colour
Total number of yellow colour cubes = 12 – 3 = 9.
Option B is the correct answer.
Question 15.
Multi-Step Tori counts the toys in her toy box. She has 3 bears and 3 cars. The rest are dolls. She has 12 toys in her toy box. How many dolls does Tori have?
(A) 9
(B) 5
(C) 6
Answer:
Tori has 3 bears and 3 cars.
Total number of toys in the toy box are 12
The rest of the toys are 12 – 3 + 3 = 6.
Option C is the correct answer.
Question 16.
Texas Test Prep What is the unknown number?
9 + _________ = 18
(A) 8
(B) 9
(C) 11
Answer:
9 is the unknown number.
TAKE HOME ACTIVITY • Hove your child exploin how using subtraction can help him or her find the unknown number in 7 + _________ = 16.
Answer:
7 + 9 = 16
Texas Go Math Grade 1 Lesson 13.4 Homework and Practice Answer Key
Write the unknown numbers. Draw 
if you need to.
Question 1.
9 + _________ = 18
18 – 9 = _________
Answer:
9 + 9 = 18
18 – 9 = 9
Question 2.
7 + _________ = 15
15 – 7 = _________
Answer:
7 + 8 = 15
15 – 7 = 8
Question 3.
12 = 8 + _________
_________ = 12 – 8
Answer:
12 = 8 + 7
7 = 12 – 7
Question 4.
_________ + 6 = 15
15 – 6 = _________
Answer:
9 + 6 = 15
15 – 6 = 9
Problem Solving
Question 5.
Mr. Brown has 7 sleeping bags. He has 16 campers. How many more sleeping bags does Mr. Brown need?
___________ sleeping bags
Answer:
Mr. Brown has sleeping bags = 7
He has campers = 16
More sleeping bags does Mr. Brown need = 16 – 7 = 9
Lesson Check
Choose the correct answer.
Question 6.
14 children are walking to raise money. 8 children finish the walk. How many children did not finish the walk?
8 + ________ = 14
(A) 4
(B) 7
(C) 6
Answer:
Children are walking to raise money = 14
Children finish the walk = 8
Children did not finish the walk = 14 – 8 = 6
Question 7.
Jasmine has 6 red pencils in her pencil case. The pencils in her hand are blue. She has 13 pencils. How many blue pencils does Jasmine have?
6 + __________ = 13
13 – _________ = 6
(A) 6
(B) 1
(C) 7
Answer:
Total number of pencils = 13
Jasmine has red pencils in her pencil case = 6
Pencils in her hand are blue.
Number of blue pencils = 13 – 6 = 7
Number of blue pencils are 7.
Question 8.
What is the unknown number?
________ + 8 = 16
(A) 8
(B) 9
(C) 7
Answer:
8 is the unknown number.
Question 9.
Multi-step Sam has 17 shirts in his drawer. He has 5 red shirts and 4 green shirts. The rest of his shirts are blue. How many blue shirts does Sam have?
(A) 9
(B) 8
(C) 10
Answer:
Total number of Sam has shirts in his drawer = 17
Total number of red shirts = 5
Total number of green shirts = 4
The remaining shirts are blue
Number of blue shirts = 17 – 5 + 4 = 8
Total number of blue shirts are 8.