E: 30/09 Win a set of Mensa branded Brain Bogglers wooden puzzles (x2)

One-Eye

Mensa Details

Entry Form

Assume you are using a basic calculator and press the numbers in the order shown, replacing each question mark with a mathematical sign. Plus, minus, multiply and divide can each be used once only. What is the highest number you can possibly score?

7 ? 8 ? 9 ? 3 ? 2 =

my answer = 66


Last month's answer: Nine of each of £1, 10p, 5p and 1p.
Congratulations to K L, Swindon, and J G, Littlehampton

wjanice121

I agree. I made it 66 too.

Kaffiness

Am I being dim? If I do this sum on paper I get 66, but on the calculator and in Excel it comes out at 77.5

7+8*9-3/2

2013yearofthehouse

Kaffiness wrote: »

Am I being dim? If I do this sum on paper I get 66, but on the calculator and in Excel it comes out at 77.5

7+8*9-3/2

Calculator/Excel is using the BODMAS method (Brackets, Orders, Division, Multiplication, Adding, Subtracting), whereas on paper you are presumably doing it from left to right

One-Eye

with brackets to make the order clear:

Using BIDMAS it is 7+(8*9)-(3/2)=77.5

Not using BIDMAS it is (((7+8)*9)-3)/2=66

This form of mensa question always specifies "simple calculator" ie. not using BIDMAS. On a "non-simple calculator" press 7+8=*9=-3=/2=

2013yearofthehouse

One-Eye wrote: »

with brackets to make the order clear:

Using BIDMAS it is 7+(8*9)-(3/2)=77.5

Not using BIDMAS it is (((7+8)*9)-3)/2=66

This form of mensa question always specifies "simple calculator" ie. not using BIDMAS. On a "non-simple calculator" press 7+8=*9=-3=/2=

Ah, not done these Mensa comps before (just explaining to Kaffiness why they were getting 2 different answers really), so wasn't aware of their "simple calculator" lingo meaning not using BIDMAS (haha it was BODMAS in my day, showing my age! )

Kaffiness

Thanks for clearing that up. I sussed it was a bracket thing, couldn't work out why the calculator & excel were putting them in automatically