Mental Math 5 th Grade

Transcription

1 Mental Math 5 th Grade 1. If a faucet drips three-hundred and four times in sixteen minutes, how many drips, on average, occurred each minute? 2. What is the radius of a circle with a circumference of thirty-six pi? 3. What is the sum of twelve, one-hundred twenty-four, and sixty-seven? 4. Start with the number of degrees in a right angle. Multiply this number by one-half. Finally, multiply by the number of sides on a rhombus. What is the final result? 5. If you have twelve pennies, fourteen nickels, three dimes, and six quarters in your pocket, how much money, in cents, do you have in total? 6. How many inches are in two yards? 7. What is twenty percent of six-hundred and twenty? 8. What is the average of the following numbers: five, twelve, eighteen, six, and fifty-nine? 9. What is the probability of rolling an even number followed by rolling an odd number using a fair six-sided die? Express your answer as a reduced fraction. 10. If you were to walk twelve yards north, five yards east, six yards south, then five yards west, how many yards will you be from your original position? 11. Suppose you biked one-hundred and eighty-two miles in fourteen hours. What was your average speed, in miles per hour? 12. What is the sum of the first five positive even integers? 13. What is the perimeter of a regular pentagon with a side length of thirteen? 14. Start with thirty-two. Multiply by five. Subtract thirty-two. Finally, divide by four. What is the final result? 15. If two x plus three is equal to nineteen, what does x equal? OVER

2 Mental Math 5 th Grade 16. What is one-fifth of the cube root of one-hundred twenty-five? 17. What is the diameter of a circle with an area of sixty-four pi? 18. If the newest vampire movie began at six forty-five p.m., and ended at ten p.m., how many minutes long was the movie? 19. Suppose a culture of bacteria doubles its mass every hour it is in existence. If one gram of the bacteria was created at nine a.m., what will the mass be, in grams, at two p.m.? 20. What is the greatest common factor of twenty-four and eighty-four?

3 Mental Math 6 th Grade 1. What is the sum of twelve, one-hundred twenty-four, and sixty-seven? 2. Start with the number of degrees in a right angle. Multiply this number by one-half. Finally, multiply by the number of sides on a rhombus. What is the final result? 3. If you have twelve pennies, fourteen nickels, three dimes, and six quarters in your pocket, how much money, in cents, do you have in total? 4. How many two-digit numbers are perfect squares? 5. What is the area of a square whose perimeter is twenty-four? 6. What is the average of the following numbers: five, twelve, eighteen, six, and fifty-nine? 7. What is the probability of rolling an even number followed by rolling an odd number using a fair six-sided die? Express your answer as a reduced fraction. 8. If you were to walk twelve yards north, five yards east, six yards south, then five yards west, how many yards will you be from your original position? 9. What is product of five-hundred and two-hundred divided by one-thousand? 10. What is the positive difference between half of two-hundred twenty-four and half of one-hundred ninety-four? 11. What is the perimeter of a regular pentagon with a side length of thirteen? 12. Start with thirty-two. Multiply by five. Subtract thirty-two. Finally, divide by four. What is the final result? 13. If two x plus three is equal to nineteen, what does x equal? 14. What is the remainder when three-hundred ninety-eight is divided by seven? 15. What is the area of a right triangle whose side lengths are twelve, sixteen, and twenty? OVER

4 Mental Math 6 th Grade 16. If the newest vampire movie began at six forty-five p.m., and ended at ten p.m., how many minutes long was the movie? 17. Suppose a culture of bacteria doubles its mass every hour it is in existence. If one gram of the bacteria was created at nine a.m., what will the mass be, in grams, at two p.m.? 18. What is the greatest common factor of twenty-four and eighty-four? 19. How many positive prime numbers are less than thirty? 20. Start with two-thirds. Multiply by one-half. Finally, multiply by six. What is the final number?

5 Mental Math 7 th Grade 1. If you have twelve pennies, fourteen nickels, three dimes, and six quarters in your pocket, how much money, in cents, do you have in total? 2. How many two-digit numbers are perfect squares? 3. What is the area of a square whose perimeter is twenty-four? 4. What is the square root of four-hundred thirty-six rounded to the nearest whole number? 5. Start with one-fourth. Take the square root. Finally, multiply by sixteen. What is the final result? 6. If you were to walk twelve yards north, five yards east, six yards south, then five yards west, how many yards will you be from your original position? 7. What is product of five-hundred and two-hundred divided by one-thousand? 8. What is the positive difference between half of two-hundred twenty-four and half of one-hundred ninety-four? 9. Start with the sum of two-fifths and one-seventh. Then multiply by thirty-five. What is the final result? 10. What is thirteen-fourths divided by one-eighth? 11. If two x plus three is equal to nineteen, what does x equal? 12. What is the remainder when three-hundred ninety-eight is divided by seven? 13. What is the area of a right triangle whose side lengths are twelve, sixteen, and twenty? 14. What is the reciprocal of two-and-one-half? Express your answer as a decimal. 15. How many unique diagonals can be drawn in a regular pentagon? OVER

6 Mental Math 7 th Grade 16. What is the greatest common factor of twenty-four and eighty-four? 17. How many positive prime numbers are less than thirty? 18. Start with two-thirds. Multiply by one-half. Finally, multiply by six. What is the final number? 19. What is the product of the number of ounces in two pounds and the number of faces on a cube? 20. What is the sum of twelve-and-a-half percent of one-hundred twenty and forty percent of onehundred?

7 Mental Math 8 th Grade 1. What is the area of a square whose perimeter is twenty-four? 2. What is the square root of four-hundred thirty-six rounded to the nearest whole number? 3. Start with one-fourth. Take the square root. Finally, multiply by sixteen. What is the final result? 4. If you roll two fair six-sided dice, what is the probability that the sum will be less than four? Express your answer as a reduced fraction. 5. If a circle has a radius of ten, what is its area, rounded to the nearest integer? 6. What is the positive difference between half of two-hundred twenty-four and half of one-hundred ninety-four? 7. Start with the sum of two-fifths and one-seventh. Then multiply by thirty-five. What is the final result? 8. What is thirteen-fourths divided by one-eighth? 9. What is the surface area of a rectangular prism with a width of ten, a height of five, and a length of twenty? 10. What is the positive difference between the least common multiple and the greatest common factor of sixteen and twenty-four? 11. What is the area of a right triangle whose side lengths are twelve, sixteen, and twenty? 12. What is the reciprocal of two-and-one-half? Express your answer as a decimal. 13. How many unique diagonals can be drawn in a regular pentagon? 14. What is the slope of a line that passes through the points with coordinates two, negative five and twelve, fifteen? 15. What is five factorial minus four factorial? OVER

8 Mental Math 8 th Grade 16. Start with two-thirds. Multiply by one-half. Finally, multiply by six. What is the final number? 17. What is the product of the number of ounces in two pounds and the number of faces on a cube? 18. What is the sum of twelve-and-a-half percent of one-hundred twenty and forty percent of onehundred? 19. If a fair coin is flipped four times, what is the probability that the coin will land heads exactly once? Express your answer as a reduced fraction. 20. What is the surface area of a cube whose volume is twenty-seven?