Math 54 Enrichment Problems

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Answers to problem sets

Activity Involves Skills Covered in Lessons 1–7

1i) Mr. Allen went to the bank. He deposited 5 hundred-dollar bills, 1 twenty-dollar bill, 7 ten-dollar bills, and 3 one-dollar bills. How much money did he deposit? Check the box next to the correct answer.

a. $593b. $693c. $793d. $493

1g) Write a three-digit number that has only one 4. Ask a friend or group of friends to do the same. Exchange papers. Write the place in which the digit 4 appears.

1f) As you walk down the street with your child, encourage him or her to look for two- and three-digit numbers on signs, buildings, and so on. Ask your child to tell you the places of the digits in each number. You might vary the activity by having your child look for numbers with a specific digit, such as 2, and then having him or her identify the place value of that digit.


Activity Involves Skills Covered in Lessons 8–14

2i) Kevin had $48 in his savings account. He was given 2 ten-dollar bills and 1 five-dollar bill for his birthday. He put his birthday money in his savings account. How much money is in his savings account now? Check the box next to the correct answer.

a. $63b. $53c. $83d. $73

2g) Work with 2 or 3 friends. Write the digits from 1 to 9 on separate index cards. Mix them up and place them facedown in a pile. Then write down a two-digit number between 10 and 30 on a sheet of paper. Turn over a card, add the number on it to the two-digit number, and record the sum. Take turns turning over the cards, adding each number to the last sum, and recording the new sum. Play until all the cards have been turned over.

2f) Play a "20" game with your child. You will need six dice or six 1–6 number cubes. The object of the game is to roll a sum of 20. Take turns rolling all the dice or number cubes at the same time. Have your child tell the sum for each roll. The first person to roll a sum of 20 wins the game.


Activity Involves Skills Covered in Lessons 15–21

3i) Terrell and Tom played a number game. Terrell picked a number that had 4 hundreds, 6 tens, and 7 ones. Tom picked a number that had 7 hundreds, 4 tens, and 5 ones. Who picked the greater number? How much greater was it? Check the box next to the correct answer.

a. Terrell; 188b. Tom; 258
c. Tom; 278 d. Terrell; 268

3g) Work with a friend. Roll three 1–6 number cubes, make the greatest three-digit number you can from the numbers you rolled, and record the number. Have your friend do the same. Together, decide which of the two numbers is greater. Then subtract the lesser number from the greater one.

3f) Place twenty to fifty pennies on a table. Ask your child to count them. Then have your child turn away while you remove some of the pennies. Ask your child to tell how many pennies you removed. Replace the pennies, and play several more times.


Activity Involves Skills Covered in Lessons 22–28

4i) Marisa and Tamika started at the same point. Marisa took 12 giant steps. Tamika took 15 giant steps. If each giant step is about a meter, about how many meters farther did Tamika walk? Check the box next to the correct answer.

a. 2 metersb. 3 meters
c. 5 metersd. 4 meters

4g) Work with a group of friends. Guess their heights in centimeters, and have them guess yours and one another's. Record the guesses. Then use a meterstick to measure one another's heights to the nearest centimeter.

4f) Ask your child to use a meterstick or centimeter ruler to measure the lengths of several objects in your home. Have your child record the names of the objects and their lengths in centimeters or, where applicable, in meters.


Activity Involves Skills Covered in Lessons 29–35

5i) Change 7 + 7 + 7 + 7 + 7 to a multiplication problem. Check the box next to the correct answer.

a. 6 x 7 = 42b. 4 x 7 = 28
c. 7 x 7 = 49 d. 5 x 7 = 35

5g) Work with a group of friends. On separate index cards, write 0 x, 1 x, 2 x, and 5 x. Mix them up and stack them facedown. On other index cards, write the digits from 0 to 9. Mix them up and place them facedown in another stack. Take turns doing the following: pick the top card from each stack; do the multiplication and record the answer; return the x card to the bottom of the stack; and put the digit card aside. Play until the stack of digit cards is gone.

5f) Talk with your child about the multiplication facts he or she is studying. Ask, "When you have several groups of the same amount, would you rather count, add, or multiply to find how many in all? Why?" Then make one, two, or five groups of up to nine small objects, such as pennies. Ask your child to find how many objects there are in all.


Activity Involves Skills Covered in Lessons 36–42

6i) What is three hundred seventeen thousand, five hundred sixty-two in expanded form? Check the box next to the correct answer.

a. 317,000 + 560 + 2
b. 300,000 + 17,000 + 562
c. 300,000 + 17,000 + 500 + 62
d. 300,000 + 10,000 + 7,000 + 500 + 60 + 2

6g) Write a four-digit number, a five-digit number, and a six-digit number. Have a friend do the same. Exchange papers. Write each other's numbers in words. Then write them in expanded form.

6f) As you read newspapers and magazines, call your child's attention to any four-, five-, or six-digit numbers you come across. Encourage your child to read the numbers aloud.


Activity Involves Skills Covered in Lessons 43–49

7i) Use the picture. To the nearest quarter inch, how long is the ribbon?

Check the box next to the correct answer.

a. 33/4 inchesb. 4 inches
c. 31/2 inchesd. 31/4 inches

7g) Trace the outline of your shoe on a sheet of paper. Write your name on the outline. Have a few friends do the same. Exchange papers. Measure the length of the outline you received to the nearest quarter inch. Record the measurement. Then exchange papers again to get a different friend's outline. Are both measurements the same? If not, talk with your friends to figure out why.

7f) Place a strip of masking tape along the length of a doorway. Have your child stand against the strip, and mark your child's height. Ask your child to use a ruler to measure his or her height to the nearest quarter inch, and have him or her record the height on a calendar. You might do this activity periodically so your child has a record of how much he or she has grown.


Activity Involves Skills Covered in Lessons 50–56

8i) Marcy had $8.05. She spent $1.35 on a notebook, 89¢ on pencils, and $1.42 on pens. How much money does she have left? Check the box next to the correct answer.

a. $4.19b. $4.39c. $4.29d. $4.49

8g) Cut out prices from old advertisements. Put them in a box or bag. Pick a price from the box or bag. Have a friend do the same. Add the prices together to find the sum. Have your partner subtract the lesser price from the greater one to find the difference. Repeat, taking turns finding the sum and the difference.

8f) As you refer to advertisements while making out your shopping list, call your child's attention to the prices of two items at a time. Ask your child questions about the prices, such as, "How much would I pay for a dozen eggs and a gallon of milk?" and "How much more do eight oranges cost than eight apples?"


Activity Involves Skills Covered in Lessons 57–63

9i) A diner received a shipment of nine packs of single-serving boxes of cereal. There were 72 single-serving boxes in all. Each pack held the same number of boxes. How many boxes were in each pack? Check the box next to the correct answer.

a. 7 boxes b. 9 boxes c. 8 boxes d. 6 boxes

9g) Write these numbers on a sheet of paper: 54, 63, 48, and 56. Work with a friend. Find which of the numbers can be divided by 6 or 9 with no remainder. Have your friend find which of the numbers can be divided by 7 or 8 with no remainder. Compare your results.

9f) Place 18 pennies on a table. Ask your child to separate the pennies into 2 equal groups, then 3 equal groups, 4 equal groups, 5 equal groups, 6 equal groups, and 7 equal groups. After each grouping, ask your child how many pennies there are in each equal group. When applicable, ask how many are left over after making equal groups.


Activity Involves Skills Covered in Lessons 64–70

10i) Mrs. Penney bought a die-cast automobile for each of her 5 grandchildren. Each automobile cost $6.78. How much money did she spend altogether? Check the box next to the correct answer.

a. $33.90 b. $36.78 c. $30.78 d. $36.90

10g) Work with a group. On separate index cards write x 2, x 3, x 4, x 5, x 6, x 7, x 8, and x 9. Mix up the cards and stack them facedown. On other index cards write the digits 0 to 9. Mix them up and place them facedown in another stack. Pick three digit cards and use the digits to make a three-digit number; then pick a multiplication card and multiply your three-digit number by the number on the multiplication card. Take turns, and shuffle the cards after each turn.

10f) With your child, look in advertisements for an item that costs $1.00 to $9.99. Ask your child how much it would cost to buy five of the items.


Activity Involves Skills Covered in Lessons 71–77

11i) Check the box next to the name of this polygon.

a. hexagon b. octagon
c. pentagon d. quadrilateral

11g) Use a ruler to draw four or five polygons. Have a friend do the same. Exchange papers. Write the names of each other's polygons.

11f) Talk with your child about the polygons he or she has been studying. Ask your child to go on a polygon hunt to find objects in your house or neighborhood that are shaped like those polygons. Encourage your child to list the objects and the polygons they are shaped like.


Activity Involves Skills Covered in Lessons 78–84

12i) Two teams scored a total of 120 points in a basketball game. Rebecca scored one fifth of all the points. How many points did she score? Check the box next to the correct answer.

a. 20 points b. 25 points
c. 30 points d. 24 points

12g) Take 48 pennies. Arrange them in equal rows. Have a friend tell you the fraction that names one of the rows, and then have him or her tell you how many pennies are in each row. Have your friend arrange the pennies in a different number of equal rows. Tell him or her the fraction that names one of the rows and how many pennies are in each row.

12f) Tell your child there are 128 fluid ounces in one gallon. Ask your child to find how many fluid ounces there are in one quart, which is one fourth of a gallon; one pint, which is one half of a quart; and one cup, which is one half of a pint. Help your child check his or her answers using water and measuring cups.


Activity Involves Skills Covered in Lessons 85–91

13i) Seven hundred forty-six peaches were in a bin. Mr. Kling put 7 of the peaches in each bag. How many bags did he fill? How many peaches were left over? Check the box next to the correct answer.

a. 108 bags; 2 peaches b. 106 bags; 4 peaches
c. 109 bags; 3 peaches d. 112 bags; 6 peaches

13g) Work with a friend. Have your friend say a one-digit number greater than 1. Roll three 1–6 number cubes and make the largest three-digit number possible using the digits you rolled. Divide that number by your friend's one-digit number. Then say a one-digit number greater than 1, and have your friend roll the number cubes, make the largest three-digit number possible, and divide.

13f) Play a "secret number" game with your child and another family member. Say a one-digit number. Have the other family member write a three-digit number, multiply it by your one-digit number, and show only the answer to your child. Ask your child to divide the answer by the one-digit number to find the secret number.


Activity Involves Skills Covered in Lessons 92–98

14i) Jennifer bought 4 notebooks that each cost $1.29. The sales tax on the total was 26¢. She paid for the notebooks with a ten-dollar bill. How much change did she receive? Check the box next to the correct answer.

a. $4.58 b. $4.48 c. $4.68 d. $4.59

14g) Play "Store" with a group. Cut out pictures of items and their prices from old advertisements. Put them on a table or counter. Take turns playing the roles of clerk, clerk's helper, and customers, as follows (you will need play money): Each customer goes to the "store" and picks out several items (pictures). The clerk's helper finds the total cost of the items. When the customer pays for them, the clerk makes change.

14f) When you go to the store with your child, talk with him or her about receiving change when paying for items. Be sure your child understands that the amount of change is less than the amount you give the cashier. Encourage your child to figure out how much change you will receive when paying for your purchases. Allow him or her to count the change.


Activity Involves Skills Covered in Lessons 99–105

15i) There are 64 fluid ounces in a half gallon. A store received a shipment of 48 half-gallon cartons of orange juice. How many fluid ounces of orange juice is this? Check the box next to the correct answer.

a. 3062 fluid ounces b. 3052 fluid ounces
c. 3072 fluid ounces d. 3042 fluid ounces

15g) Roll two 1–6 number cubes, use the digits you roll to make a two-digit number, and record the number. Have a friend do the same. First estimate the product of the two numbers and record the estimate, and then find the exact product. Have your friend do the same. Check to see how close your estimates were to the exact product.

15f) Talk with your child about the usefulness of estimating a product before multiplying. Discuss everyday occasions when estimation comes in handy, such as making sure you have enough money to make several purchases. Then help your child find examples of two-digit numbers in newspapers or magazines. Ask him or her to explain how to estimate the product of a pair of these numbers. Then have him or her find the exact product.


Activity Involves Skills Covered in Lessons 106–112

16i) Ramon scored 96, 84, 88, and 92 on math quizzes. If he has an average score of 90 or higher, he will be on the math team. What is Ramon's average score? Will he be on the math team? Check the box next to the correct answer.

a. 88; no b. 90; yes c. 92; yes d. 89; no

16g) Write down 2 two-digit numbers. Have a friend do the same. Together, try to find the average of the four numbers. Was there a remainder when you divided? Work together to change one or two of the numbers so the sum can be evenly divided.

16f) Encourage your child to measure each family member's height to the nearest inch. Ask your child to find the average height of the family members. If there is a remainder after your child divides, help him or her round the answer to the nearest whole number of inches.


Activity Involves Skills Covered in Lessons 113–119

17i) Sally lives 85.6 kilometers away from Grandmother's house. Her cousin, James, lives 59.75 kilometers away from Grandmother's house. How much closer to Grandmother's house does James live? Check the box next to the correct answer.

a. 26.75 kilometers closer b. 25.75 kilometers closer
c. 27.75 kilometers closer d. 25.85 kilometers closer

17g) Write down four decimal numbers to tenths on separate index cards. Have a friend write down four decimal numbers to hundredths on separate index cards. Mix all the index cards together. Pick two cards, add the decimal numbers on them, and have your friend subtract the decimal numbers on them. Show each other the answers. Then have your friend pick two cards and add the decimal numbers on them while you subtract the decimal numbers on them. Show each other the answers again. Repeat the activity as often as you and your friend would like.

17f) Ask your child to keep an ongoing record for a week or two of the money he or she spends and receives. Encourage your child to find and report the total amount he or she has at the end of each day.


Activity Involves Skills Covered in Lessons 120–126

18i) Mr. Lee bought two parcels of land. One was 6/10 acre and the other was 3/10 acre. Then he sold off 5/10 acre. How much land was left? Check the box next to the correct answer.

a. 6/10 or 3/5 acre b. 2/10 or 1/5 acre
c. 5/10 or 1/2 acre d. 4/10 or 2/5 acre

18g) Write all the eighths fractions (1/8, 2/8, 3/8, and so on) on separate index cards. Mix them up. Have a friend pick two of the fractions. Subtract the fractions, and have your friend add them. Continue until all the fractions have been used. Then repeat the activity using all the tenths fractions. This time, pick the fractions and add, and have your friend subtract.

18f) Talk with your child about using fractions in everyday life, such as in cooking or in measuring in inches. Let your child experiment with measuring cups. Ask him or her to pour 1/3 cup water into a larger measuring cup. Ask, "What fraction of a cup would you have if you poured in 1/3 cup more?" Encourage your child to predict before he or she completes the experiment. You might also direct your child to pour in 3/4 cup water and then pour out 1/4 cup of it, predicting how much water will be left.


Activity Involves Skills Covered in Lessons 127–133

19i) What is the probability of the spinner's stopping on B?

Check the box next to the correct answer.

a. 1/4b. 1/2c. 1/3 d. 2/3

19g) Work with a friend or a group. Cut different numbers of squares from several colors of construction paper. Count the number of squares of each color and write the numbers on a small paper bag. Then write the total number of squares on the bag. Together, figure out the probability of picking each color and record it in its simplest form. Put the squares in the bag and shake it. Take turns picking one square from the bag. Each time you or a friend picks a square, record its color and return it to the bag. Continue until together you have made as many picks as there are squares in the bag. Compare the results of your experiment with the probabilities you wrote on the bag. Talk about the results.

19f) Talk with your child about the probability of a coin's coming up heads or tails when it is flipped. Ask, "Suppose we flipped a coin twenty times. How many times do you predict it would come up heads?" Work with your child to do the experiment. Keep a tally of the result of each flip. Talk with your child about the results.


Activity Involves Skills Covered in Lessons 134–141

20i) Use words to write the number 321709012.

20g) Write a nine-digit number. Have a friend write another nine-digit number. Exchange papers. Use words to write each other's number. Then underline a digit in each other's number. Exchange papers again. Tell each other the place of the underlined digit.

20f) Help your child find examples of seven-, eight-, and nine-digit numbers in newspapers, magazines, and reference books such as almanacs. Ask your child to read the numbers aloud. You might vary the activity by reading the numbers to your child and asking him or her to write them.