Monday, 14 November 2016

KS2 Maths Challenge: No 2

Your challenge is to use the numbers available (50, 75, 9, 8, 7 and 5) and the four operations (addition, subtraction, multiplication and division), to make the target number of 640.

Each card can only be used once. It may not be necessary to use all the cards.

How close to 640 can you get? 
How many different ways can you make 640?
What is the most efficient way to make 640?

59 comments:

  1. i had 50 i times by 9 i got 450 then i calculated to get 225 then i added 450 225 then i got675 i took away 9 5 8 then i got 651

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    1. i think i calculated wrong

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  2. Add 340 to 300 and you'll end up getting 640

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  3. 75+50=125 125X5=625 625+10 = 635

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    1. Great Miguel, but can you get closer?

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  4. I can get to 639 that is how much I can get to

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  5. 640-0=640
    640 divided by 1 =640
    100 times 4=400+200+40=640
    1,000 -500=500+140=640

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    1. Read the question carefully Chinemey. You can only use the following numbers: 50, 75, 9, 8, 7 and 5.

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  6. 50x12=600+50=650-5=645-5=640

    75x8=600+5+5+5+5+5+5+5+5=640

    8x80=640

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    1. You can only use each of the numbers once Reo. How did you get 12?

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    2. 75×9=675 8+7=15 675-50=625+15=640

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  7. Adrian class 6 red7:12 am, November 22, 2016

    320 + 320 = 640 I got 640 by halfing the number 640 which gave me 320 and adding 320 together that's how I got 640

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    Replies
    1. Read the question again Adrian.

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    2. You can't use 320

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  8. 530 +110= 640

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  9. First I do 50+75=125 then they do 9+8=17 then I do 17+7=24 now I do is I add 125+24= 149 then I do 149 time 5 I get 745 take away 50 I get 695 I do 5+5= 10 I take away 10 =685 685 take away 5= 680 then I take way 50 is 630 now I do 5+5=10 now I do 630+10=640

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  10. 75+50=125
    125x5=625
    625+8=633
    633+7=640

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  11. 50X9=450 9X8=72 7X5=35 450+72=522 522+35=557 557+75=632

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  12. 75+50x5=625+9+7=641
    I used the biggest numbers first then I x it to make 645 later I added 9 and 8 which was 642 but I took away the 8 and added 7 instead to make the closest number to 640

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  13. 70x9=630+8=638+5=643

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  14. First try 9x8x7+75+50=629

    Second try 75x9=675-50=625+15=640
    8+7=15


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  15. 540+100=640
    641-640
    640 divide 1=640
    740-100=640
    100x4=400+200+4

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  16. 75+50=125
    125x5=625
    8+7=15
    625+15=640

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    Replies
    1. Well done Reo! Are there any other ways of making 640?

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  17. 75+50=125
    125×5=625
    625+8=633
    633+7=640

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  18. 75+25=125
    125×5=625
    625+8=633
    633+7=640

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  19. The closest I got was v
    641

    75x8=600+50=650-9=641

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  20. 75 + 25 = 125
    125×5=625
    625+8=633
    633+7=640

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  21. 75×9=675 675-5×7=640

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  22. We could try 300+300=600 now I am going to ad 40 to 600 600+40 will give you 640

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  23. Let's do 650-10 will give you 640.

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  24. You could do 200+300=500 then 500+40=540 and I am going to add 540 to 100 540+100= 640

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  25. 75+50=125
    125x5=625
    625+8=633
    633+7=640

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  26. 125x2.5+2.5+625+4+4+633+7=640

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  27. 75x9=675
    675-8=666
    666-5=661
    Can you get closer?

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  28. 50x9=450
    450+75=525
    9x8=72
    525+72=597
    7x5=35
    597+35=632
    That was the closest I got to but I'm going to keep on trying until I get to the answer!!

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  29. 75x9=675
    675-7=668
    668-8=660

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  30. 50+75=125
    125x5=625
    625+9=634
    634+8=642
    642+7=649

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  31. 75x8=600
    600+50=650
    650-9=641

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  32. 50+75=125
    125x5=634
    634+7=641
    641+8=649
    649-9=640

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  33. I got 640. I calculated 50+75=125×5=625+7=632+8=640

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  34. 75+50=125
    125x5=625
    625+8=633
    633+7=640

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  35. 75x9=675
    675-50=625
    625+7=632
    632+8=640

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  36. 100+25=125
    125 times 5=625
    625+15=640

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  37. 75x9=675
    675-50=620
    8+7+5=20
    620+20=640

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  38. 1280 divided by2=640
    5x128=640
    6x100=600+40=640

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  39. 50x8=400 9+400=409 8-409=401

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  40. 75x8=600
    600+50=650
    650-9=641
    That is the closest I can get to 640 but I have made other different ways of making the number with only using these numbers 50,75,9,8,7,5.

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  41. 75+25=125
    125×5=625
    625+8=633
    633+7=640

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  42. 75x8=600
    600+50=650
    650-9=640

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  43. 600+40=640 Is An Ovias One 650-10=640 6x100=600+40=640 600+70=670-30=640 900-300=600+40=640 Well That's All I Have So Far.

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  44. 75x9=675
    7x5=35
    675-35=640

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  45. 75+50=125
    125x5=625
    8+7=15
    625+15=640

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  46. 75+50=125
    125x5=625
    8+7=15
    625+15=640 or 75x9=675
    7x5=35 675-35=640

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  47. 31+33=64 5+5=10 64x10=640

    ReplyDelete