## Envision Math 4th Grade Textbook Answer Key Topic 2.9 Subtracting Across Zeros

Draw a Picture and Write an Equation

The mass of a human brain is how much greater than the mass of a chimpanzee brain? Guided Practice*

Do you know HOW?

Question 1.
In one week, Sandy earned $36 from her babysitting job. She got$15 more for doing her chores. How much money did Sandy earn? Question 2.
How can you show that 930 grams is a reasonable answer for the question asked above?

Question 3.
Write a Problem Write a problem using the table at the top. Solve. Draw a picture to help you.

Independent Practice

Question 4.
Four cities are on the same road that runs east and west. Fleming is west of Bridgewater but east of Clinton. Union is between Fleming and
Bridgewater. It is 21 miles from Fleming to Union. It is 55 miles from Clinton to Union. How far is it from Clinton to Fleming?

Question 5.
Scott and his friends walk to school together. Scott leaves his home at 7:00 A.M. He meets Johnny and Zach at the end of the block. Next, they meet Paul, Tim, and Pete. Dan and Torey join them one block before the school. How many friends walk to school altogether?

What do I know?
The average mass of a chimpanzee brain is 420 grams. The average mass of a human brain is 1,350 grams.

What am I asked to find?

The difference between the masses

Plan and Solve

Draw a picture. Write an equation. Use subtraction to solve.
1,350 – 420 = The human brain has a mass that is 930 grams more than the chimpanzee brain.

Question 6.
The American Kennel Club recognizes 17 breeds of herding dogs and 26 breeds of terriers. Draw a picture that could help find the total number of herding dogs and terriers.

Question 7.
Using the information in Exercise 6, write an equation to find how many more breeds of terriers than herding dogs there are.

For 8 through 10, use the table to the right. Question 8.
There are about 200 more animals in the Minnesota Zoo than in the Phoenix Zoo. About how many species of animals are in the Minnesota Zoo?

Question 9.
About how many more species are in the Indianapolis Zoo than the Phoenix Zoo?

Question 10.
How can you find the number of species of animals at the San Francisco Zoo?

Question 11.
A parking lot had a total of 243 cars in one day. By 6:00 A.M., there were 67 cars in the lot. In the next hour, 13 more cars joined these. How many more cars would come to the lot by the end of the day? Question 12.
A shoe store sold 162 pairs of shoes. The goal was to sell 345 pairs. How many pairs of shoes did they NOT sell? Independent Practice

For 13 and 14, use the table at the right. Question 13.
What equation can you write to help find the cost of the shoes and socks together?

Question 14.
What equation can you write to help find the difference between the cost of the shirt and the shorts?

Question 15.
Byron spent $7.75 on popcorn and a drink at the movie theater. The popcorn was$4.25. How much was the cost of the drink? Question 16.
Each school day, Mikaela sold the same number of tickets to the school play. On Monday she sold 4 tickets. How many tickets did she sell all together in 5 days? Question 17.
Writing to Explain Ken makes 2 nametags in the time it takes Mary to make 5 nametags. When Mary has made 15 nametags, how many has Ken made?

Question 18.
Mr. Lee had 62 pencils at the beginning of the school year. At the end of the school year he had 8 pencils left. How many pencils were given out during the year? Question 19.
Carlene bought a book for $13.58. She paid with a$10 bill and a $5 bill. Which expression would find the amount of change Carlene would receive? A.$15 – $13.58 B.$15 – $1.42 C.$10 + $5 D.$13.58 + \$1.42

Question 20.
Terrence rode 15 rides before lunch at the county fair. He rode 13 rides after lunch. Each ride requires 3 tickets. Which expression
represents the number of rides he rode during the day?
A. 15 – 13
B. 15 + 13
C. 15 – 3
D. 13 – 3

Stop and Practice

Find each sum. Estimate to check if the answer is reasonable.

Question 1. Question 2. Question 3. Question 4. Question 5.
5,474 + 723

Question 6.
47,090 + 2,910

Question 7.
6,685 + 37

Find each difference. Estimate to check if the answer is reasonable.

Question 8. Question 9. Question 10. Question 11. Question 12. Question 13.
5,302 – 88

Question 14.
2,249 – 51

Question 15.
8,001 – 4,832

Error Search Find each sum or difference that is not correct. Write it correctly and explain the error.

Question 16. Question 17. Question 18. Question 19. Question 20. Number Sense

Estimating and Reasoning Write whether each statement is true or false. Explain your answer.

Question 21.
The number 213,753 is ten thousand more than 223,753.

Question 22.
The sum of 6,823 and 1,339 is greater than 7,000 but less than 9,000.

Question 23.
The sum of 42,239 and 11,013 is less than 50,000.