Math Problems of the Day 140 Warm-Ups for 8th Graders Problem # 1 How many ways can you represent the number of dots shown? Problem # 2 The answer is 7. What is the question? (Make it a good one! :) Problem # 3 What is the BIGGEST 9-digit number you can make? What is the SMALLEST 9-digit number you can make? Put each of your answers in a place value chart! Problem # 4 Grown-ups round numbers all the time in real life. Write down as many examples as you can think of when this might happen. Problem # 5 Joni bought a pad of notebook paper for $0.50. She bought two pencils for $0.69 each. She bought a used backpack for $3.78. She lives in Oregon, where there is no sales tax, and she paid with a $10.00 bill. How much change should she get back? Problem # 6 For lunch, Brady can choose between two soups (minestrone or chicken noodle) and three drinks (water, milk, or chocolate milk). What are all the possible combinations he has to choose from? Problem # 7 Happy Hollow Elementary had a canned food drive. 6th graders donated 462 cans. 5th graders donated 298 cans. 4th graders donated 507 cans. About how many cans did the school raise altogether? Problem # 8 Lucy danced for a total of one hour, practicing jazz, tap, and ballet. She practiced twice as long on jazz as she did on ballet. She practiced tap twice as many minutes as ballet. For how many minutes did she practice ballet? Problem # 9 The table below shows the enrollment of students at Schmappy Schmallow Elementary: Grade Level Number of Students Kindergarten 195 First 182 Second 207 Third 173 Fourth 148 Fifth 159 Sixth 196 What is the difference between the LARGEST class and the SMALLEST one? Problem # 10 A model kit has 100 pieces. The kit has long beams, short beams, and connectors. There are 20 long beams and 30 short beams. Ann builds a bridge from 62 pieces. How many pieces does she have left? Write an equation to represent this problem! Problem # 11 Patty is, right now, 3 times as old as her brother Terry. In 10 years, the sum of their ages will be 36. How old are they right now? Problem # 12 In June 2010, a fourth-grade class planted a tree in the schoolyard. The tree grew about 3 inches per year. If the tree was 38 inches high in June 2015, about how high was the tree when it was planted? Problem # 13 Mrs. Fernandez has to run a few errands before her TV show comes on at 7:00 pm. She has to mow the lawn (45 minutes), go grocery shopping (an hour), stop by the post office (15 minutes), and walk her dogs (45 minutes). What is the latest time that she can leave the school to get everything done and be ready for her TV show at 7:00 pm? Problem # 14 Joe made a frozen yogurt shake with 10 ounces of milk and some strawberry frozen yogurt. He used the mixture to fill three 5-ounce glasses, and had 2 ounces left over. How much frozen yogurt did he use? Problem # 15 The difference between two numbers is 3. Their sum is 47. What are the numbers? Problem # 16 What is the thirteenth number in this series? 1, 1, 2, 3, 5, 8, 13, 21, 34... Problem # 17 The Boilermaker Special passes by my house every 6 minutes. The Lafayette City Bus passes by my house every 15 minutes. The trolley passes by my house every 10 minutes. All three passed by my house at the same time at 6:00 pm. When is the next time that will happen? Problem # 18 I am a number less than 100. Two of my factors are 3 and 5. My digits are 1 apart. What number am I? Problem # 19 A birthday present for Mrs. Psarros costs $24. How much less will each teacher pay if 4 teachers share the cost equally than if 3 teachers share the cost? Problem # 20 Attendance at the National Typewriter Show has been decreasing each year. It was 2,000 in 2011; 1,750 in 2012; 1,500 in 2013; and 1,250 in 2014. If the drop-off continues at the same rate, in what year will NO ONE attend anymore? Problem # 21 The sum of two numbers is 27. The difference of the same two numbers is 3. What are the two numbers? Problem # 22 For Thanksgiving, a family of 9 is trying to share 4 storebought pies fairly. If each pie is pre-cut into 8 slices, and everyone gets the same number of slices, how many slices will be left over? Problem # 23 Ashlyn and Brooke went to the arcade with $12. They bought 4 bottles of water, which cost $1.50 each. They each bought a sticker book for $1.25 each. Ashlyn put $0.50 in a fundraiser jar. A game of pool cost $3 per game. Did they have enough money left to play? Problem # 24 A single school bus has 15 rows, with 2 seats in each row. Each seat holds 3 children, or 2 adults, or 1 adult and 1 child. Four 4th-grade classes are taking the bus on a field trip. The classes each have 22 students, 1 teacher, and 2 chaperones. Will they have to take one bus, or two? Problem # 25 Students holding a Car Wash Day washed 12 cars in the first hour, 15 cars in the next hour, and 10 cars in each of the next 4 hours. They earned $60 in the first hour, and $50 in the third hour. How much money did they earn in all? Problem # 26 If you triple a number, you will have one-half the number of hours in two days. What is the number? Problem # 27 At Nose for Clothes, Inez bought a T-shirt for $12.50 and a pair of jeans for $5 more than twice that price. She paid with a $50 bill. What change should she get back? Problem # 28 In 1983 (the year Mrs. Fernandez was born), the world’s lowest temperature was recorded in Antarctica. In degrees Fahrenheit, the thermometer dropped to 160 degrees below freezing (true story). What was the temperature? Problem # 29 The world’s longest foot race took place in 1929. It took the winner 11 weeks, 48 hours to complete the 3,665-mile New York-to-Los Angeles event (true story). How many days did it take him? Problem # 30 What is the tenth number in the series below? 1, 2, 4, 8, 16, 32... Problem # 31 Which fraction is greater, 3 ¼ or 3 ⅙? PROVE IT with a picture! Problem # 32 Bryce has 15 coins in his piggy bank. All are nickels and dimes. They total $1.35. How many of each type of coin does he have? Problem # 33 Charlie went to McDonald’s for a Happy Meal. He could choose a cheeseburger, hamburger, or chicken nuggets as the main course. He could choose between french fries and apples as a side, and he could choose between soda, juice, or chocolate milk to drink. How many combinations of a happy meal are possible? Problem # 34 You want to plant a rectangular garden that has an area of 12 square feet. To keep pests away, you want to put up a fence--but it’s expensive! So you want to use the least amount of fencing (ordered by the foot) as possible. How much fencing will you need? Problem # 35 It is 1,518 miles from West Lafayette to Provo, UT (where Mrs. Fernandez started in college). If I drive in that direction 692 miles the first day and 674 miles the second day, how many more miles will I have to drive the third day until I reach my destination? Problem # 36 If you double a number, you will get the same as the triple of one-fourth of 24. What is the number? Problem # 37 A rectangle is 7 inches by 11 inches (7” x 11”). A square has the same perimeter. What is the area of that square? Problem # 38 Mandy had a box of chocolate malted milk balls. She ate 5 and gave her brother 3. Then she passed around the remaining milk balls to her 8 friends. The first friend took 1, the second friend took 3, the third friend took 5, and so on, with each team member taking the next higher odd number of milk balls. There were just enough milk balls in the box for the last team member to take her correct amount. What was the original number of milk balls in Mandy’s box? Problem # 39 Bill buys 4 boxes of candy, each of which has 8 chocolates inside. He has 5 sisters. If he is generous and gives an equal number of chocolates to each sister (and the MOST number each sister could receive), how many chocolates will Bill have left over for himself? Problem # 40 How many seconds are there in one day? Problem # 41 Name a time where the two “hands” of an analog clock would form a right angle. (BONUS: How many times does a right angle form on the clock face each day?) Problem # 42 For his reading goal this nine weeks, Jeonhee wants to read 1,000 pages. The first week he read 10 pages per day. The second week he read 15 pages per day. The third week he read 20 pages per day. How many more pages does he need to read to reach his goal? Problem # 43 After participating in the world’s biggest marble hunt, you started a marble collection. You have 11 jars, and each jar can hold up to 28 marbles. You have filled 7 ½ jars so far. How many marbles do you have? Problem # 44 The average school day in the U.S. is 8 hours long, Monday-Friday. Several small towns have toyed with the idea of a four-day school week, though, with extra hours added on each day to make up the time. How much longer would an average school day be in this case? Problem # 45 Naomi caught half as many fish as Jack did. Together they caught 18 fish. How many fish did Jack catch? Problem # 46 Evan and Grant are brothers. They earned an equal allowance, and they pooled their money to buy a videogame that cost $22.00. The cashier gave them $8.00 back. How much money did each boy offer to begin with? Problem # 47 Which is a better deal per ounce--a 16-oz bag of M&Ms that costs $3.20, or a 2-oz bag of M&Ms that costs $0.50? Problem # 48 A farmer raises chickens and pigs. If he has twice as many chickens as pigs, and there are 160 feet out of all the animals combined, how many pigs does he have? Problem # 49 Abby, BJ, and Coraline ran a relay race. They finished the race in one hour. Abby’s leg took ½ of the time, and BJ’s leg took ⅓ of the time. For how many minutes did Coraline have to run? Problem # 50 The answer is 0.01. What is the question? (Make it a good one...or two!) Problem # 51 If there were 25 questions on a math test, and McKinstry got 22 of them correct, what grade did she get? Problem # 52 Michael had a great basketball game the other day. He scored 35 of his team’s 62 points! If he made 5 three-pointers and no single-point foul shots, how many baskets did he make in all? Problem # 53 The math team went out to eat and ordered 7 eight-slice pizzas. What fraction of the total amount of pizza ordered is left after 40 slices are eaten? Express your answer as a fraction in simplest form. Problem # 54 A medium pizza from Pizza Hut is cut into 8 slices and costs $7.99. If there are 13 guests at your party, and each person needs at least two slices (it’s okay to have leftovers), how much money will you spend on pizza? Problem # 55 You’re making cookies for a bake sale, so you want to triple the recipe you usually use. You estimate that you have about 7 cups of flour left. If the original recipe calls for 2 ¼ c. flour, will you have enough flour to make the cookies, or will you have to run to the store to buy more? Problem # 56 I have some stickers in my collection. My sister has 29 more than I do. Together we have 773 stickers. How many stickers are in my collection? Problem # 57 One-half of one number (let’s call it “x”), added to one-fourth of 96, is 30. What is the number “x”? Problem # 58 A square has a perimeter of 28 inches. Another square has a perimeter of 20 inches. What is the difference of their areas? Problem # 59 Jennifer and Pete are going to play Scrabble. The number of tiles of each letter is in the chart above. To determine who will go first, they will each randomly select one letter, without replacement, from the bag containing all of the letter tiles. The person who selects a letter closest to A goes first (if they both draw the same letter they will draw again). Jennifer draws first and selects an E. What is the probability that Pete’s selection will result in Pete going first (without having to redraw)? Problem # 60 Benson and Jenson are twins born one minute apart. Benson celebrated his 3rd birthday anniversary on February 29, 2016, while Jenson has had 12 birthday anniversaries. What is the month, day, year and time of Jenson’s birth? Problem # 61 Leap day happens every four years. 2016 was a leap year, as was 2012, etc. How many days have you been alive? Problem # 62 Emma and Uriah are going on a camping trip. They scooped up kernels of popcorn to roast over the fire and put the kernels in baggies. Emma used a ¼ c. scoop three times, and Uriah used a ⅓ c. scoop twice. Who packed more popcorn kernels? Problem # 63 Some ants can lift up to 50 times their body weight. The current world record (as of 2014) for a 105 kg man for lifting a barbell is 242 kg. If this man was as strong as the strongest ant (relatively speaking), by how many kilograms could he exceed his current world record? Problem # 64 How many real-life jobs can you list (in two minutes) that actually use math? Problem # 65 You wanted to earn a little money, so you made a lemonade stand over a long weekend. The first day you sold 17 cups. The second day, you sold 8 more than that. The third day, you sold 3 cups less than the second day. How many cups did you sell in all? Problem # 66 A salamander is sneaking through the forest, trying to avoid predators--but he does spot several blue jays and raccoons. Between the two species, he counts 16 heads and 42 legs. How many of each animal did he see? Problem # 67 Mrs. Fernandez and six of her younger siblings have ages that are consecutive. When they moved from Battle Ground to southern Lafayette, their ages (all seven of them) added up to 91. How old was Mrs. Fernandez when they moved? Problem # 68 Quadra, a quirky pirate, has 100 gold coins to put into four different bags. He puts them in so that each bag has two more coins than the one before. How many coins are in each bag? Problem # 69 David is buying fish for his aquarium. Clown fish cost $12 each and angel fish cost $7 each. If he has $100 to spend, and he wants to spend every dollar, how many of each fish can he buy? Problem # 70 Macy, Nawaar, and Orson ran a relay race in one hour. Macy took ⅖ of the time. Nawaar ran ¼ of the time. For how many minutes did Orson have to run? Problem # 71 Aeryn spent 5 days building a brick wall that had 100 bricks in it. She got better each day and managed to lay 4 more bricks than the previous. How many bricks did she lay her first day? Problem # 72 Gage is training for a mini marathon (13 miles). He wants to run on Mondays, Wednesdays, and Saturdays. The first day (a Monday) he will run 1 mile. If he adds a half mile to his run each time that he runs, in how many weeks will he be trained to run 13 miles? Problem # 73 I have a box of chocolates that is 9 chocolates high by 5 chocolates wide. If I eat 2 rows of chocolates, how many chocolates do I have left? Problem # 74 The answer is 4/8. What is the question? Problem # 75 Insert symbols to make a true equation with the numbers below: 1 2 3 4 = 5 Problem # 76 Solve the rectangle puzzle below so that each side of the rectangle has a sum of 20. 4 5 9 1 3 Problem # 77 Newton made up a “code” where he put letters in the place of numbers. He only used the digits 1, 2, 3, and 4. Here are the numbers in code: #1) cabd #2) bdca #3) badd #1 is the greatest and #2 is the least. #3’s digits add up to 7. Which letters stand for which numbers? Problem # 78 Put the coins above in order so that: ● ● ● ● The first three coins add up to 12 cents. The last three coins add up to 16 cents. The pennies are not next to each other. The last coin is not a dime. Problem # 79 Put the coins above in order so that: ● There is one coin between the two pennies. ● There are two coins between the two dimes. ● The first coin is not a penny. Problem # 80 If you start with 3 ones and 12 tens, how many more tens will you need to add to get to the number 233? Problem # 81 Find the missing number to make the scale balance. 3 4 5 6 ? Problem # 82 Juan had 138 Lego bricks. He also had two containers and divided them equally between the two. He had 14 bricks left over. How many Lego bricks did each container hold? Problem # 83 Sam, Carla and Sarah spent on afternoon collecting sea shells. Sam collected 11 shells. Carla collected three more than Sam. In all, the three friends collected 34 shells. How many shells did Sarah collect? Problem # 84 Fill the the blanks to make a pattern: ___, 2, 6, 24, ___, ___ Problem # 85 What is the tenth number in the sequence below? 1, ½, ¼, ⅛, 1/16, ... Problem # 86 There are 4 ponds and 22 frogs. No more than 15 frogs can fit in a single pond. If each pond is filled with a DIFFERENT odd number of frogs, how many frogs are in each pond? Problem # 87 There are five students in line: ● Ava is somewhere between Jude and Emmet. ● Katie and Ava are standing next to each other. ● Jude, who is last, and Maggie are not standing next to each other. ● Emmet is not at either end of the line. ● There are two people between Katie and Maggie. What is the line order? Problem # 88 A bicycle show featured some bicycles and some tricycles. There were 25 wheels in all. If there were 5 bicycles shown, how many tricycles were shown? Problem # 89 I am a four-digit number. ● ● ● ● The sum of all four digits is 15. My tens digit is twice my thousands digit. I am an odd number. My ones digit is four less than my hundreds digit. ● I am not divisible by 5. What number am I? Problem # 90 What is the next number in the sequence below? (In other words, how many dots would there be in the next picture?) Problem # 91 What is the difference in the number of factors between 24 and 50? Problem # 92 Which is greater, 8/3 or 2 ½? Prove it! Problem # 93 Insert symbols to make a true equation with the numbers below: 50 6 7 8 Problem # 94 What is the eighth number in the sequence below? 1, 4, 9, 16, 25, 36... Problem # 95 Each shape below stands for a digit so that the equations are true. Which digit could each shape represent? Problem # 96 Fill in the blanks for this simple sudoku so that each row, each column, and each bolded box has each of the digits 1,2,3 and 4: Problem # 97 Four people are in a Friendship Club. Each week they make sure they’ve talked on the phone oneon-one to the other three people in the club. At least how many conversations occur each week between the four friends? Problem # 98 What is a regular solid shape that has half as many vertices as a pentagonal prism? Problem # 99 Find the value of “x” to make the scale balanced. 1 3 6 x x Problem # 100 I am a three digit number. ● My tens digit is twice as big as my ones digit. ● My hundreds digit is half as big as my ones digit. ● All three digits add up to 14. What number am I? Problem # 101 Is the number 5,287,734 divisible by 3? How can you tell? Problem # 102 Complete these sentences with “odd” or “even.” If you add two even numbers, you get an ______ number. If you add an odd and an even number, you get an ______ number. If you add two odd numbers, you get an ______ number. Problem # 103 How many triangles do you see in this picture? Problem # 104 The answer is 37. What is the question? (Make it a good one...or two!) Problem # 105 Here’s a cool math trick: 1) Write down any three-digit number where each digit goes down by one each time (eg. 765, 321, 987, etc.). 2) Reverse that number (so 567, 123, 789, etc.), and then find the difference between the two numbers. Write that difference down in a new place. 3) Take that new number and reverse it. Add the difference and the reversed difference together. Your answer is ... 1,089! Problem # 106 Start at 4 on the number line below. Go +3, -8, +2, -6, +9. Where do you end up? Problem # 107 The sum of two prime numbers, who are 10 apart on a number line, is the product of 6 and 8. What are the two prime numbers? Problem # 108 What is the twelfth number in the sequence below? 1, 1, 2, 4, 7, 11, 16, 22... Problem # 109 Vivian is starting a simple savings account. The first day she puts in 1 penny. The second day she doubles it (puts in 2 pennies). The third day she doubles it again (4 pennies), and so on, doubling the amount each day. How much money will she have saved up after 10 days of this? Problem # 110 You are drawing a giraffe next to a tree. The actual giraffe is 16 feet, but in your picture it is only 8 inches tall. The tree next to it is 20 feet tall. How tall should the tree be in your picture to keep it to scale? Problem # 111 Fill in the blanks for this simple sudoku so that each row, each column, and each bolded box has each of the digits 1,2,3 and 4: Problem # 112 Here is a map you’ve drawn of Treasure Island. Pirate Pete is coming in on the ship for a treasure-hunting vacation. He wants to find buried treasure for sure, but he doesn’t know what else to do. Can you (as his travel agent) plan out a fun vacation for him, giving him at least 4 things to do IN ORDER so that he’s not walking back and forth over the whole island, AND give him the coordinates or directions to each activity? Problem # 113 Austin likes to watch squirrels find and store acorns for the winter. Brown Squirrels can carry two acorns at a time. Gray Squirrels can carry three acorns at a time, and Black Squirrels can carry five acorns at a time. There is a pile of 24 acorns. How many more trips would a Gray Squirrel need to make to store all of the acorns in the pile than would a Black Squirrel? Problem # 114 If you start at a number and go +2, then -7, you end at -2. At which number did you begin? Problem # 115 Find the value of x to make the scale balanced. x 12 17 21 x x Problem # 116 What is a regular solid shape that has half as many faces as a hexagonal prism? Problem # 117 The answer is 45 degrees. What is the question? Problem # 118 You and your older sister want to go see a dino exhibit at the museum three times this month (your parents would drop you off). Which plan would be the best use of your money and fit your needs? Problem # 119 What is the first time of the day in which all the digits of the time are different prime numbers? What about the last time of day in which that’s the case? Problem # 120 What is the ninth number in the series below? 174, 164, 155, 147, 140... Problem # 121 Put the coins above in order so that: ● The two quarters are not touching, but one of them is first. ● The dime and the penny are not touching, and have two coins between them. ● The nickel and dime are right next to each other, and neither are on the end. Problem # 122 Emilie loves cats and she keeps some as pets. All but two of them are completely black. All but two of them are completely white. All but two of them are completely ginger. How many cats does Emilie have in all? Problem # 123 Music is FILLED with math! In the example below, you have 4 beats in each of the first two measures and 2 beats in the third measure. The notes are like fractions of a whole; a whole note lasts the whole measure, or in these cases 4 beats, while a half note only lasts 2. A quarter note would be one beat, then. If we changed all the notes to sixteenth notes, how many sixteenth notes would it take to fill these three measures? Problem # 124 I am a fraction in simplest form that is equivalent to a decimal that is 15% less than 40%. Problem # 125 If you subtract a number from the square of 7, you will get onefourth the product of 9 and 8. What is the number? Problem # 126 Pascal’s triangle looks like this (though it continues downward infinitely): Write down as many patterns and observations as you can about it in three minutes. Problem # 127 Fill in the blanks for this simple sudoku so that each row, each column, and each bolded box has each of the digits 1,2,3 and 4: Problem # 128 I am the seventh number in the following sequence of numbers: 1, 3, 7, 15… What number am I? Problem # 129 Three consecutive numbers have a sum of 135. What are the numbers? Problem # 130 I am a three-digit number that is divisible by 7, but not by 2. The sum of my digits is 4. What number am I? Problem # 131 If you start at a number and go +5, then -1, then +2, then -3, then +5, you get to the number 1. At which number did you begin? Problem # 132 Find the value of x to make the scale balanced. x 40 60 x 70 x Problem # 133 I am a fraction equivalent to ⅜. My denominator is 20 greater than my numerator. What fraction am I? Problem # 134 A triangle’s three angles add up to 180 degrees. In triangle ABC, the degree measure of angle A is 20° greater than the degree measure of angle B. Angle C is a right angle. What is the measure of ∠B? Problem # 135 Over a period of 6 hours, the temperature rose 4℉, rose 3℉ more, dropped 2℉, rose 1℉, dropped 2℉, and then dropped 3℉ more. The temperature at the end of the 6-hour periods was -5℉. What was the starting temperature? Problem # 136 Put the coins above in order so that: ● The first three coins are equal in value to the 5th coin. ● The nickel does not touch any pennies. ● The sum of the 2nd and 3rd coins is 15 cents. Problem # 137 When the square root of one number is multiplied by the square root of a second number, the product is the square root of 36. One of the numbers is not 1. What are the two numbers? Problem # 138 The Washington Monument is 100 feet taller than the Great Pyramid of Giza. If the Washington Monument and the Great Pyramid each were 355 feet shorter, the Washington Monument would be twice as tall as the Great Pyramid. How many feet tall is the Washington Monument? Problem # 139 I am the fewest number of fish that meets the following conditions: When netted by threes, by fours, or by fives, there is always one left over. What number am I? Problem # 140 A huge frog ate 140 big bugs in 5 days. Each day, it ate 8 more bugs than it did on the previous day. How many bugs did the frog eat on the first day?