Can you solve this easy mental math problem?

[distancia]

More importantly, I am looking for the steps--every single, tiny step--in solving this problem. I want to see how a "math brain" versus a "non-math brain" thinks, or if there is even a difference. Tell me if you stared off into space, if you saw the numbers written down. Where did your eyes go? What did you see in your mind, if anything? What did you do with the numbers to solve the problem?

 

So, please don't bias yourself by reading others' answers before attempting to solve on your own. It is a very easy problem, I promise! No pencil or paper, though. Just your own brain. Here goes: multiply forty-seven by six

 

 

Thanks. :001_smile:

Edited November 22, 2011 by distancia
add a smiley for thank you

[amtmcm]

I immediately convert the words into numbers and visualize the numbers in my brain. Then I multiply 40x6 and 7x6 and add them together.

[Mom22ns]

I have a non-math brain.

 

I multiplied 7x6 got 42, held onto the 4 mentally. Multiplied 4x6 got 24+4 =28 and stuck the 2 back on the end for 282.

[Carrie12345]

7x6, put down the 2, carry the 4. 4x6, 24 plus 4. 282.

 

And I'll feel really dumb if my scrolling back and forth on the iPad messed me up!

[Acorn]

I immediately convert the words into numbers and visualize the numbers in my brain. Then I multiply 40x6 and 7x6 and add them together.

 

 

Same here. I don't know how I would classify a math brain vs non math brain. I love math and have used it as part of my career.

[Elinor Everywhere]

I multiplied 4x6 and added a zero. Then I multiplied 7x6 and added it to the first number.

[MeaganS]

I immediately convert the words into numbers and visualize the numbers in my brain. Then I multiply 40x6 and 7x6 and add them together.

 

:iagree: Except then I got stuck because I never learned my times tables in school and have learned most of them over time but 6x7 always gets me, so then I started doing some addition to figure out what 6x7 was.

[Belacqua]

Resident math-minded person did it this way:

 

47*3=141 (because 40*3=120 and 7*3=21)

Then: multiply 141 by 2 (because 3*2=6) to get 282.

[freesia]

More importantly, I am looking for the steps--every single, tiny step--in solving this problem. I want to see how a "math brain" versus a "non-math brain" thinks, or if there is even a difference. Tell me if you stared off into space, if you saw the numbers written down. Where did your eyes go? What did you see in your mind, if anything? What did you do with the numbers to solve the problem?

 

So, please don't bias yourself by reading others' answers before attempting to solve on your own. It is a very easy problem, I promise! No pencil or paper, though. Just your own brain. Here goes: multiply forty-seven by six

 

 

Thanks. :001_smile:

282

I looked at the numbers, multiplied 40x6, "wrote it" on a board in my head, multiplied 7x6, added it to 40x6.

[Embassy]

I did 40x6 and then 7x6 and added them together. I didn't visualize them. I just looked at the words on the screen. Now if it was presented auditorily I would have needed to write it down or visualize it.

 

I have no idea if I have a math brain or not. It was one of my best subjects in school, but I didn't enjoy it.

[MyThreeSons]

I can usually do these types of problems much more quickly mentally than I can with a pencil and paper or even a calculator.

 

Here's how I would do it:

 

(40 x 6) + (7 x 6) = 240 + 42 = 282.

 

HTH

[Chris in VA]

I can usually do these types of problems much more quickly mentally than I can with a pencil and paper or even a calculator.

 

Here's how I would do it:

 

(40 x 6) + (7 x 6) = 240 + 42 = 282.

 

HTH

 

This is me, too--only I did the 42 first for some reason. I see the numbers and my eyes go to the side. If that makes any sense! lol

I can't keep the numbers in my head if I do it the algorithm way, but I do it that way on paper.

[Jen500]

I did

50*6=300

then subtracted (3*6)

 

I didn't 'see' anything, just had words in my head

[aggieamy]

I did

50*6=300

then subtracted (3*6)

 

I didn't 'see' anything, just had words in my head

 

This is exactly how I did it. Well, I don't know if Jen mumbled to herself like I did while she was doing it but beside that this was the same method I used.

[Joan in GE]

I did 40x6 and then 7x6 and added them together. I didn't visualize them. I just looked at the words on the screen.

 

Same here.

[JustGin]

Stare into space, think 6x4=24, add the zero to represent the 10, so 240, then 7x6=42, add to get 282.

 

FWIW, I am not "mathy" and my brain doesn't hold numbers in view for long, so for an even slightly more complex problem for example, 47x48, I would use paper and pencil, because I know the algorithm but my brain would drop numbers from my short term memory before I got them all worked out.

[bcnlvr]

I immediately convert the words into numbers and visualize the numbers in my brain. Then I multiply 40x6 and 7x6 and add them together.

 

This.

[Sevilla]

Have not read other responses. Here is how I do it in my head:

 

47x6 = 7x6 = 42 (hold that thought)

4x6 = 24 therefore 40x6 = 240

 

240+42

4+4=8

40+40=80

80+2=82

200+82=282

 

Answer = 282

[JohnLacey]

I looked at the word "by" probably longer than most. And I thought about the number 7. It's always been a tricky number for me. Then I thought, maybe I should just use a calculator, but I didn't allow myself to cheat. I then multiplied each number individually, like a traditional vertical multiplication problem, in my head. Carried the 4 and came up with 282.

[beaners]

I set it up like a traditional problem in my head, visualizing the numbers and where they would go as if I had written it on paper.

 

47

x6

 

For me, it is faster to do this type of problem traditionally in my head. If it was more complicated I would have broken down the number into more convenient chunks or used nearby "round" numbers. In this case it was easier for me to just figure out the answer than brainstorm strategies. I enjoy math and have done well in it.

[Nan in Mass]

I'm moderately mathy. First I looked away from the screen and repeated the words a few times until I visualized the two numbers. Once I had visualized them, I realized that this was going to be an easy problem, something that I could do using the standard algorithm rather than doing something more creative (like changing the 47 to 50, doing the problem, and then subtracting the 24). Then I multipled 40 by 6 and 6 by 7. I visualized the 240 under the first two numbers and added the 42 to it. When I say that I multiplied and added, I didn't really multiply and add because the numbers are simple - I just knew the answer. The whole time I was doing this, there was a voice in my head but I ignored it unless I got distracted and needed to revisualize the numbers I was working with. I was looking to the left of the computer screen as I did it. I did not grow up being able to do mental math. Nobody pointed out that I could visualize the numbers if I wanted to remember them and vocalize other numbers, or needed to see a part of the number. I also didn't know my multiplication tables well. Instead, given a problem like this, I would have chopped it up into little pieces, pieces small enough that I oculd deal with them without knowing my times table, and then added the pieces together - something like 40x3 + 40x3 + 7x3 + 7x3. I would then have added the two 100s together and then mentally set them aside and ignored them until the end, when I would have put them back in. Meanwhile, I would have dealt with the 20+20+21+21, probably by thinking of it as 4 2's with a zero added to the right and two 1's. Getting it all back together correctly without using visualization to store the inbetween numbers would have been a challenge. My arithmetic was often wrong. I was fairly good at the complicated problems, though.

 

Nan

[SKL]

50 x 6 minus 3 x 6.

[silliness7]

I immediately convert the words into numbers and visualize the numbers in my brain. Then I multiply 40x6 and 7x6 and add them together.

 

That's what I did only I stared off into space and for some reason I couldn't see it as 40 x 6. The answer wasn't coming. I had to see it/think it as 6 x 40. I don't know why.

 

ETA: I am *not* a math person and I learned this mental math technique a few years back from our Developmental Math curriculum. Before that I would have been scrambling for pencil and paper.

Edited November 22, 2011 by silliness7

[laundrycrisis]

I have not read any other replies.

 

47x6

 

First I would multiply 40 by 6 = 240

Then 7x6=42

Adding 240+42 is easy, 282

[angela in ohio]

40x6 = 240

7x6=42

240+42=282 (I did this by adding the 40 to 240 first and then the 2)

 

We have done a lot of mental math stuff around here, so this is much faster for me than working it out in the traditional way in my head. It took me just a second to say the answer - thanks to my math teachers in school drilling us with our facts, and a lot of "contest math"/"mental math" work with dds.

[Deniseibase]

It's 3 off from 50, so thought, I can do 50 times 6, which is 300, minus 3x6, which is 18, so, uh, subtract 20 from 300 is 280 plus 2 is 282. As you might be able to tell, I get lazy and would rather do a lot of easy sums than a couple hard ones :) Plus it takes MUCH longer to write it down than to do it :-) I don't think I'm a math brain, I flunked Algebra the first time I took it and passed it with a C- the second time, but my husband says I am a math brain so take it with a grain of salt.

[kiana]

47*6=(50-3)*6=300-18=280+2=282.

 

ETA: Having read some other posts and reread the directions :D

 

Didn't stare anywhere. Didn't see the numbers in my head. I'm absolutely horrible at visualizing anything (failed art, too) but manipulating numbers and text has always been very easy.

Edited November 22, 2011 by kiana

[Teachin'Mine]

I don't think I have a math brain, but I picture the problem written with the multiplication sign and the line below. I then do 6 x 7 and mentally write down the 2 and carry the 4. Then I do 6 x 4 and add the 4 to get 28 and remember the last number is 2 for 282.

 

I can also do 6 x 50 to get 300 and subtract 3 x 6 is 18 to get 282. I usually round numbers anyway to make sure my answer is in the ballpark and makes sense.

[Miss Marple]

I always find it easiest to round to the closest "10". So in this case I multiplied 50 by 6. I know that 5 x 6 is 30 then add another zero. Then I subtracted 47 from 50 and got 3 because I used 3 more (6 times) than I needed. Multiplying the 3 by 6 I got 18 (no real thinking on that). Then I subtracted 18 from 300 by taking 20 away from 300 to get 280 and adding the 2 back that I get when I subtract 18 from 20.

 

That's how my thought process went - although it went much faster than it took time to write :) That's how I would teach my kids as well.

[chepyl]

I did 7*6 and 40*6 in my head then added 42 and 240 to get 282.

[Lori D.]

I immediately convert the words into numbers and visualize the numbers in my brain. Then I multiply 40x6 and 7x6 and add them together.

 

 

This was my method, too.

[Halcyon]

I immediately convert the words into numbers and visualize the numbers in my brain. Then I multiply 40x6 and 7x6 and add them together.

 

This. I look into 'my mind's eye' and visualize seeing the numbers in front of me. Then I multiply 40x6 and get 240. I "hold" that in my head, then do 7x6 and get 42. Then I 'see" that 4 tens plus 4 tens equals 8 tens, and 0 +6 is 0.

[happyhomemaker]

I immediately see it as a vertical problem with 47 on the top. 6X7 is 42. I see the 2 written at the bottom of the problem and the 4 written over the 4 in 47. 6X4+4 is 28. I see the 28 written in front of the 2 at the bottom of the problem. The answer is 282.

 

Getting the answer seems cumbersome when I write it out, but it really doesn't take long at all. I always did well in math and have a minor in math, but I know that being good at math and being "mathy" are sometimes different things. Not sure if I am "mathy" or not.

[Renee in NC]

More importantly, I am looking for the steps--every single, tiny step--in solving this problem. I want to see how a "math brain" versus a "non-math brain" thinks, or if there is even a difference. Tell me if you stared off into space, if you saw the numbers written down. Where did your eyes go? What did you see in your mind, if anything? What did you do with the numbers to solve the problem?

 

So, please don't bias yourself by reading others' answers before attempting to solve on your own. It is a very easy problem, I promise! No pencil or paper, though. Just your own brain. Here goes: multiply forty-seven by six

 

 

Thanks. :001_smile:

 

I multiplied 50 times 6 and then subtracted 18.

[OLG]

I set it up like a traditional problem in my head, visualizing the numbers and where they would go as if I had written it on paper.

 

47

x6

 

For me, it is faster to do this type of problem traditionally in my head. If it was more complicated I would have broken down the number into more convenient chunks or used nearby "round" numbers. In this case it was easier for me to just figure out the answer than brainstorm strategies. I enjoy math and have done well in it.

 

This was me as well...Can't say I enjoyed ALL of math (like trig) but generally like it.

[Sebastian (a lady)]

I thought of what 50 * 6 would be (300). Then subtracted 3*6 from it in two steps (300-10, then 290-8).

 

However, when I was a kid, I would frequently "draw" the problem in the air with my finger and work it out as if it were on paper.

[Laura in CA]

didn't read the replies yet, but I multiplied 50 by 6 (300), and then subtracted six 3s (18) to get 282. Well, that last step (subtracting 18) I actually subtracted 20, I guess, and then added 2.

 

My dad taught us stuff like this (short cuts) on long car rides.

[klmama]

I multiplied 40 x 6, then 7 x 6, then added them together to get 282. Each time while I did the multiplication, I looked up. No math brain here. I think I learned to multiply that way from Singapore. It's much faster than my old way of doing it, and I don't forget what I got for the first step (in this case, multiplying the tens place).

 

Before I learned that trick, I would have tried to do it the way I would on paper, just in my head and using my fingers to hold the numbers, if possible. So, for 6 X 7 = 42 I would hold the 2 on my right hand, the 4 on my left. Then 6 X 4 = 24 plus the 4 on my left hand is 28, then the 2 on my right for the ones place is 282. I had to use my hands to keep track of the numbers, because I would forget whatever the ones place answer was while I was figuring out the tens.

[kiana]

I multiplied 40 x 6, then 7 x 6, then added them together to get 282. Each time while I did the multiplication, I looked up. No math brain here. I think I learned to multiply that way from Singapore. It's much faster than my old way of doing it, and I don't forget what I got for the first step (in this case, multiplying the tens place).

 

 

Lol ... yeah ... plus that way if you get bored halfway through at least you're close :D

[KAR120C]

multiply forty-seven by six

Forty times six is 4x10x6, and I know 4x6 is 24... so that's 240. Then hold on to that, and seven times six is 42... so 240... 280... 282. As of the 240+42 part I see the numbers in my head, but the stuff before that is just memorized times tables.

[Mona100]

I looked off into space and saw this 47

x6 and then I worked out the 7x6 part by remembering (seven times tables were hard for me) 6x6 is 36 so it had to be the 42. Then I carried the 4 over and multiplied 4x6=24+4=28. I had to remember the 2 at the end so that's how I got 282. I am definitely not math inclined.

[specialmama]

More importantly, I am looking for the steps--every single, tiny step--in solving this problem. I want to see how a "math brain" versus a "non-math brain" thinks, or if there is even a difference. Tell me if you stared off into space, if you saw the numbers written down. Where did your eyes go? What did you see in your mind, if anything? What did you do with the numbers to solve the problem?

 

So, please don't bias yourself by reading others' answers before attempting to solve on your own. It is a very easy problem, I promise! No pencil or paper, though. Just your own brain. Here goes: multiply forty-seven by six

 

 

Thanks. :001_smile:

 

When reading the first word in the problem, "multiply", I immediately saw a big red X. I then had to picture 47 numerically, then the words "by six" made me move the number 6 to the front, so it would look like 6 X 47. I then froze for a minute, stared into space, and reached for a calculator. :lol: I am not a mathletic. :lol:

[go_go_gadget]

Another vote for 40x6=240 and 6x7=42, and then 240+42=282. I can never decide whether I'm "mathy", even though I'm a math major, because I can never remember algorithms unless I understand them fully, so the all-memorization-no-conceptual-understanding style used to teach us math in school left me hating math and thinking I could never do it. Once I started learning math on my own and playing with it I, though, I starting loving it. I still can't remember and use a formula if I don't understand it inside and out, however. I'm like a compiler, and if I come to something I can't execute I can't continue, my brain just aborts.

[KarenNC]

6x7 is 42, 4x6 is 24 then x10 so 42 + 240 is 282. Don't know how my eyes moved, I'm afraid, but they usually go down and to the right when I'm thinking.

 

As to whether I'm math-oriented, I don't know. Finished through calculus easily, did not do well with linear algebra or ordinary differential equations.

[Cindyg]

multiply forty-seven by six

 

50 x 6 = 300

 

50-47=3. 3 x 6 = 18.

 

300 - 20 = 280

 

The difference between 20 and 18 is 2. So 280 + 2 = 282.

 

This is not how I would have done it if you had allowed a pencil and paper; but since you specified, this is how I would do it.

[edithcrawley]

I visualized a piece of paper with the following;

 

47

x6

---

?

 

Then I worked through each step mentally as I would if it were on paper, ending with the following visual: (though in my head the little 4 on the top was smaller than the other numbers)

 

4

47

x6

---

282

 

 

ETA: not very mathy

Edited November 23, 2011 by jennifermarie
Forgot to say if I was mathy or not

[Kareni]

I did 40x6 and then 7x6 and added them together. I didn't visualize them. I just looked at the words on the screen.

 

This was the method I used as well.

 

Regards,

Kareni

[Caitilin]

I have not read any other replies.

 

47x6

 

First I would multiply 40 by 6 = 240

Then 7x6=42

Adding 240+42 is easy, 282

 

This is how I do it too; but I have to say it to myself first. Or rather, say it as I mentally do it. I am proficient at math but not mathy. :001_smile: very word oriented.

[justasque]

Well, there are lots of things I could do, but I think I'm going to multiply 50 by 6, so I'll double up the 50's to make 100's so there are three pairs so that's 300. Then I have to subtract 3 times 6, which I already know is 18, so 300 minus 10 is 290, then take another 8 which is 282 (basically 290 minus 10 is 280 plus there is the two that with 8 makes 10, so you add the two back in).

 

Then to check my work I'll think about the formal written method, so 6 by 7 is 42, and then 6 by 4 is 24 (really 240 because the 4 is really 40), so add them and get 282. That checks, so 282 is my answer.

 

ETA - I'm very mathy.

Edited November 23, 2011 by askPauline

[Hunter's Moon]

I automatically imagine 47 over 6 and multiPly like that. I use my fingers in the air. So I see 47 over 6 and multiply 7 and 6 which is 42. Then, I carry the 4 over and multiply 4 and 6 and get 24. Then, I add the 4 that I carried over and get 28. The answer is 282.

 

Yeah, I know, it's a bit more complicated than mental math should be, but I HAVE to use. Fingers in the air to do it or nohing will connect in my brain. I'm a very 'hands-on, need to touch to learn' learner. I'm also not very math-y.