multiplication | MathCelebrity Forum

multiplication

  1. math_celebrity

    111,111 x 111,111 no calculator

    Solve this with no calculator. From left to right, count from 1 to 5 Then write 6 Then count down from 5 to 1 12,345,654,321
  2. math_celebrity

    If each box contains 6 apples, and there are 8 boxes, how many apples are there in total?

    If each box contains 6 apples, and there are 8 boxes, how many apples are there in total? Total Apples = Number of Boxes * apples per box Total Apples = 8 * 6 Total Apples = 48
  3. math_celebrity

    Multiply two-digits numbers by 11 shortcut

    53 x 11 Write 3 as the right most digit in 53 3 5 + 3 = 8. Write that to the left of 3 83 Then write the 5 as the left most digit 583 35 x 11 Write 5 as the right most digit in 35 5 3 + 5 = 8. Write that to the left of 5 85 Then write the 3 as the left most digit 385 57 x 11 Write the 7 in 57...
  4. math_celebrity

    Multiply by 49 No Calculator Shortcut

    we start at the top and write 4 and add 5 for every line we go down: 49 * 1 = 4 49 * 2 = 9 49 * 3 = 14 49 * 4 = 19 49 * 5 = 24 49 * 6 = 29 49 * 7 = 34 49 * 8 = 39 49 * 9 = 44 49 * 10 = 49 Next, we start the bottom of the list. add on a 0 at the end, and for each line we go up, we add 1 more...
  5. math_celebrity

    Multiply by 39 No Calculator Shortcut

    we start at the top and write 3 and add 4 for every line we go down: 39 * 1 = 3 39 * 2 = 7 39 * 3 = 11 39 * 4 = 15 39 * 5 = 19 39 * 6 = 23 39 * 7 = 27 39 * 8 = 31 39 * 9 = 35 39 * 10 = 39 Next, we start the bottom of the list. add on a 0 at the end, and for each line we go up, we add 1 more...
  6. math_celebrity

    (98)^2 no calculator mental math

    Round 98 to the nearest 10. This is 100. Call this a. Calculate b which is a - our original number: b = 100 - 98 b = 2 We can use this formula: (a - b)^2 = a(a- 2b) + b^2 Given a = 100 and b = 2, we have: (100 - 2)^2 = 100(100 - 2(2)) + 2^2 98^2 = 100(96) + 4 98^2 = 9600 + 4 98^2 = 9,604
  7. math_celebrity

    3-By-1 Mental Math Multiplication

    987 x 9 ------ Break apart 987: 900 + 80 + 7 So we have: 900 * 9 = 8100 80 * 9 = 720 7 * 9 = 63 Add them up and we get 8,883
  8. math_celebrity

    Multiply Even Numbers by 5 No Calculator Shortcut

    Take the number being multiplied by 5. Divide it in half Add a zero 14 * 5 Divide 14/2 = 7 Add a 0 --> 70
  9. math_celebrity

    Multiply by 29 No Calculator Shortcut

    we start at the top and write 2 and add 3 for every line we go down: 29 * 1 = 2 29 * 2 = 5 29 * 3 = 8 29 * 4 = 11 29 * 5 = 14 29 * 6 = 17 29 * 7 = 20 29 * 8 = 23 29 * 9 = 26 29 * 10 = 29 Next, we start the bottom of the list. add on a 0 at the end, and for each line we go up, we add 1 more from...
  10. math_celebrity

    Multiply by 19 no calculator shortcut

    we start at the top and write 1 and add 2 for every line we go down: 19 * 1 = 1 19 * 2 = 3 19 * 3 = 5 19 * 4 = 7 19 * 5 = 9 19 * 6 = 11 19 * 7 = 13 19 * 8 = 15 19 * 9 = 17 19 * 10 = 19 Next, we start the bottom of the list. add on a 0 at the end, and for each line we go up, we add 1 more from...
  11. math_celebrity

    If j = –1 and k = 16, what is k + 16j

    If j = –1 and k = 16, what is k + 16j Plug in our numbers: 16 + 16 * -1 16 - 16 0
  12. math_celebrity

    6 & 1/8 x 1/7

    6 & 1/8 x 1/7 Using our fraction calculator, we get: 7/8
  13. math_celebrity

    In the year 1989, Luke's age was 3 times Rachel's age and Rachel's age was 3 times Dan's age. If Dan

    In the year 1989, Luke's age was 3 times Rachel's age and Rachel's age was 3 times Dan's age. If Dan's age was n, how old were Rachel and Luke? Rachel's age = 3 * Dan's age Rachel's age = 3n Luke's age = 3 times Rachel's age Luke's age = 3(3n) Luke's age = 9n
  14. math_celebrity

    If sound travels 1/5 of a mile in one second, how many miles does it travel in 1/5 of a second?

    If sound travels 1/5 of a mile in one second, how many miles does it travel in 1/5 of a second? 1/5 mile / second * 1/5 second = 1/25 of a mile
  15. math_celebrity

    The sound from a thunderstorm travels approximately 1/5 of a mile in one second. How far will the so

    The sound from a thunderstorm travels approximately 1/5 of a mile in one second. How far will the sound travel in 18.6 seconds? 1/5 mile per second * 18.6 seconds = 3.72 miles
  16. math_celebrity

    Approximately 2,800 red blood cells are created in the bone marrow each second. How many red blood c

    Approximately 2,800 red blood cells are created in the bone marrow each second. How many red blood cells would be created in .03125 seconds? 2800 red blood cells / second * .01325 seconds = 87.5 red blood cells
  17. math_celebrity

    I have 150 bags of candy. I need 5 candies for every one bag. How many candies do I need?

    I have 150 bags of candy. I need 5 candies for every one bag. How many candies do I need? Candies = Number of bags * candies per bag Candies = 150 * 5 Candies = 750
  18. math_celebrity

    If you save $110 in one month, how much will you save in one year?

    If you save $110 in one month, how much will you save in one year? 110 per month * 12 months in a year = 1,320 saved in a year
  19. math_celebrity

    50 is how many times as big as 20

    50 is how many times as big as 20 50/20 = 2.5
  20. math_celebrity

    There are 60 students in a class. Three-fourths of them are girls. How many boys are there

    There are 60 students in a class. Three-fourths of them are girls. How many boys are there In the class, we have either boys or girls. Total students = 60 3/4 of 60 = 60 * 3/4 Since 60/4 = 15, we have: 15 * 3 = 45 girls Boys = 60 - girls Boys = 60 - 45 Boys = 15
Back
Top