(5 times 4 squared) divided by 2 =? Can You Solve In Your Head?
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- čas přidán 3. 06. 2024
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Do the power first (16), then multiply by 5 to get 80, then divide by 2 = 40
I did iot ythe same way and got 40.
I got 40 also
Got the answer in my head before the video. I like mental math and at the age of 71 it is my way of exercising my brain to avoid dementia.
You may enjoy Nerdle.
Same!
That was how I did this formula.
Me too.
At 73, likewise.
I think your explanation and scribbling made the problem so much harder than it needed to be. I had the answer in two seconds, and I'm old.
I've quit listening. I just do the problem, post my answer, then go through the other answers to see if my answer is the same. If not, I'll suffer through his boring explanation.
Took me four seconds, am old too but was a boiler maker, not a maths fundi.
@@deonlouw1198 I was neither, but for my career, my math skills that I needed were positive and negative numbers. Addition and subtraction. When they realized how good I was at my job, I was trained to use every piece of equipment that also were used to determine exactly what they needed to do for each eye or every patient. that had either cataract or refractive surgery. There were other things I did as well, but they had nothing to do with math, only my skill with a high powered camera that focused on the blood vessels in the retina.
Took me only a few seconds; 5 × 16 is 80, half of which is 40.
I got 40 before the video loaded.
Before video, I did it in my head quickly, getting 40, then checked it with calculator. I don't even need to watch video.
You make it way harder than it has to be, way harder.
My husband does crossword puzzles to keep himself sharp, I watch your channel! In our early 60s, it’s now pretty fun. When I was in Pharmacy school, I used to balance equations to relieve STRESS!!! One really DOES get rusty even with pharm calc every DAY! Thanks for sharing your expertise!
Interesting. I did an electronics course in my late 30s' ...an accelerated program from unemployment insurance, a 2 years into 1 type thing.
Extremely math heavy...everything but calculus. Hours of homework every night, all kinds of formulas etc. I aced every exam we had, had it mastered, so to speak.
Now nearly 70, I can't recall most of it, lol.....like, I love watching these little videos John puts out, & my mind says....ya... I got this...then it's.....oh wait....hmmm.... damn.... I _used_ to know how it's done, lol
I'm now not sure if it's more stressful to me trying to remember, or stress relieving working my old brain.😵💫😜
It took me less than a minute to solve that in my head!
And I’m by no means a maths fan.
A 2 minute explanation in 14 minutes !
I did get 40, but I love these videos because sometimes I don't get it right, and I enjoy the refreshers. I'm 57 by the way, so keep them coming. 😅
nice
Well, truth to tell, PEMDAS isn't shackles. Sometimes it's irrelevant. Evaluating left to right, 5 * 1/2 * 16 = 1/2 * 16 * 5 = 16 * 5 * 1/2. Or, if you want to be snarky, 4^(2-1/2) *5 works just as well as the problem as stated.
It's all 40. You can't change that no matter where you put the parentheses in this equation. Multiplication is commutative. Division isn't - but if you convert division to a multiplication by reciprocal, it's still commutative.
Because of the parentheses the stupid magic Decoder Ring of PEMDAS is not even useful. I see many of us did it visually in under ten seconds.
we write it as: (5 × 4 × 4)/2
4 and 2 cancels out, resulting in: 5 × 4 × 2 = 40
Clever answer
No calculator needed: 5 x 16 = 10 x 8 = 80 then 80 / 2 = 40 Tatadadaa ta tatadadaaa !
Today I practiced this: buying new headphone $ 220 but when you got to the shop the price is increased with 18%. What is the new price? My students were calculating and came up with $ 39.60... did not see that the answer must be higher than 220. They calculated almost correct, just missed the old price.
Percentage = (new price minus old price) / old price so 18/100 = (N - 220) / 220 so 3960 / 100 = 39.6 = (N - 220)
so the new price is N = 39.6 + 220 = $ 259.6
Also a nice route: 1.18 x 220 = 1 x 220 + 2 x 22 - 2 x 2.2 = 220 + 44 - 4.4 = 264 - 4.4 = $ 259.6
There is more than one way to figure. I began with 4x4=16 (5x10)+(5x6)=50+30=80/2=40 I used distribution because I do not have 16x5 in my memory. This is why math talk is important. It is a part of the new teaching process in teaching math. I would have needed pencil and paper without distributive property. My first grade students use associative property in math. Often they are quicker than I am.
Same here. Ten times anything is simpler than five times anything. Quicker and easier that way.
Now I remember why I hated math in middle school, should have taken less than a minute.
got it 40 thanks for an easy pemdas.
Solved it in my head in 40 tenths of a second.
I think your clock is running a bit slow, probably the battery.
4 seconds
My old aunt Sally does suggest 40
Thank you for the fun math problems.
Break time is my opportunity to play with numbers. I'm
63 yrs. old , working in Construction.
Oh !
And I worked out 40 for the answer in my head , and hung around for the answer too.
Thanks to the PEMDAS I did do it in my head!!
Thanks to not using PEMDAS (which I despise because it can't be trusted to actually be implemented) I did it like most of us did: 5 times 16 is ten times 8... 80/2=40.
I think your explanations are perfect for people who are trying to learn how to think about math and solve problems. If a person has minimal amount of experience your explanations are necessary.
Can someone tell me what grade this math is?
The foundations of mathematics have long grappled with seeming paradoxes surrounding concepts like continuity/discreteness, infinity, and the nature of mathematical reality itself. The both/and logic of the monadological framework provides a novel way to model and integrate these poles in a coherent foundational framework.
Continuity and Discreteness
A core issue in mathematical ontology is the relationship between the continuous and the discrete - the challenge of bridging the realms of calculus/analysis dealing with the infinite divisibility of continuous quantities, and arithmetic/algebra dealing with the indivisible natural numbers and discrete structures.
The multivalent structure of both/and logic allows formulating nuanced perspectives that integrate the continuous and discrete using coherence valuations. We could model a given mathematical object/system with:
Truth(continuous properties) = 0.7
Truth(discrete properties) = 0.5
○(continuous, discrete) = 0.6
Here the object is represented as partially continuous and partially discrete, with these seemingly contradictory aspects exhibiting a moderate degree of coherence.
The synthesis operation ⊕ further models how novel mathematical entities can arise as integrated wholes transcending this continuous/discrete opposition:
continuous differential structure ⊕ discrete algebraic encoding = geometric object
This expresses how mathematical objects like manifolds are coconstituted by the synthesis of both continuous and discrete elements into irreducible gestalts. Trying to reduce them to either pole alone is an artifact of classical either/or thinking.
The holistic contradiction principle allows formalizing how any continuous structure necessarily implicates underlying discrete elements/infinitesimals, and vice versa:
continuous differentiable curve ⇐ discrete infinitesimal displacements
discrete arithmetic progression ⇐ continuum of intermediate points
Infinity and The Infinite
Another foundational paradox is the problematic relationship between the finite and the infinite - the status of infinite sets, infinitesimals, limits, and absolute infinities within mathematics. These stretch classical logic.
Both/and logic allows assigning distinct yet integrated truth values to finite and infinite descriptors:
Truth(set is finite) = 0.6
Truth(set is infinite) = 0.5
○(finite, infinite) = 0.4
This captures the partial truth of infinite set descriptions like the continuum while avoiding absolute bifurcation of finite/infinite.
The synthesis operation models the emergence of transfinite set theory:
finite initial segments ⊕ perpetually generative procedures = transfinite set
This expresses the coconstitution of infinite sets from the complementary synthesis of discretely finite kernels and infinitely iterative processes of continuation.
Holistic contradiction further allows formalizing the self-undermine paradoxes intrinsic to the infinite within arithmetic itself:
finite natural number ⇒ innumerable higher powers and derivatives
bounded arithmetical system ⇒ inexpressible infinities and paradoxes
This captures how even the most discretely finite mathematical concepts already transcendentally enfold and depend on transfinite idealities from a higher vantage.
Logicism and Mathematical Reality
Another foundational debate concerns the ontological status of mathematical objects - whether they are abstract timeless entities existing in a Platonic realm, or are mere symbolic fictions constructed by human minds and practices. Both extremes face paradoxes.
Both/and logic provides a nuanced perspective integrating these poles. We could have:
Truth(math is objective Platonic reality) = 0.4
Truth(math is subjective human construction) = 0.5
○(objective, subjective) = 0.7
This models mathematics as involving moderate degrees of both objective/realistic and subjective/constructed aspects in coherent integration.
The synthesis operation expresses how new irreducible mathematical structures emerge precisely through the syncretic coconstitution of objective logical constraints and subjective creative exploration:
objective logical constraints ⊕ subjective human practices = novel mathematical structures
From this view, mathematics is neither absolutely objective nor subjective, but an irreducibly intersubjective collective truth regime emerging from the reciprocal determination of rational order and open-ended inquiry.
Furthermore, holistic contradiction allows formalizing the semantic paradoxes that undermine any attempt to reduce mathematical reality to either absolutely objective/subjective:
purported objective logical reality ⇒ self-undermining paradoxes
subjective linguistic constructions ⇒ inherent rational necessities
This expresses how purely subjective or objective accounts already subvert themselves and implicate their apparent opposite as an intrinsic moment.
In summary, both/and logic allows rethinking and reformulating many core issues in the foundations of mathematics:
1) Integrating the continuous and discrete into a synthetic pluralistic ontology
2) Bridging the finite and infinite through contextual coherence measures
3) Modeling mathematical objects as intersubjective truth regimes
4) Formalizing the self-undermining paradoxes that undermine absolutist accounts
By refusing to reduce mathematical reality to any one pure pole like the objective, subjective, finite, infinite, continuous or discrete, both/and logic opens up an expanded, relationally holistic foundation more befitting the nuances of actual mathematical inquiry. Its multivalent, synthetic structure aligns with the irreducible complementarities and transcendent unities haunting classical approaches.
Rather than trying to eliminate mathematical paradoxes through either/or resolution, both/and logic allows productive integration and deployment of these intrinsic contradictions as prestigious phenomena guiding us deeper into the subtle dynamic realities underlying mathematics itself. By reflecting this syncretic ontological openness directly into its symbolic grammar, the monadological framework catalyzes revitalized foundations for an emboldened, recursively coherent investigation of mathematical truth.
So I asked my magic 8 ball and it replied: "don_t bother me, i_m watching Penn and Teller". It_s never said that before.
I just divided my age by 2. (kidding LOL not dead yet)
I'm nearing 80, so all my maths education was well before anyone thought of PEMDAS or BODMAS. But it's a pretty straightforward question and I got the answer in a few seconds.
Honestly, I had to think about this one as the computer on the shoulders was only fitted with memory in MB while we are in a GB world now. No blue screen so I guess that's good.
40
5x4x4=80
80/2=40
If 1+3 how many minutes you can solve that?
AS a dyslexic person who has always found maths hard there type of questions make me feel stupid . So now o do t look at them 😕
Algo boost!
At time stamp 10:00 you went off in a direction that is going to confuse a lot of non math folk. Might I suggest that you just run the math as 5x16=80 and 80/2=40. It just seems to me that you went off on a math tangent that's going to turn off people that already struggle with math concepts. J.M.T.C.
Yep, very easy!
…yes, but I have a Mathematics Academic degree; if you do any Algebra, you can do this in your head.
Woot Ty
40 in about five seconds in my head. Sorry it took so long. I haven't had breakfast yet.
Basically, ill respect how you did your math :), i mean everyone has their own way, but i count It in 1 second using my head before i start this video
4² = 16, 5 x 16 = 80 ( I remember this mutiplication since My parents usually test me with a 2 digit with 1 digit multiplication, and 2 digit with 2 digit) after that just divided by 2 = 40. Ok
The answer is YES I CAN!
PEMDAS is worth remembering when programming but this problem is too simple for that. I always see x5 as a half times ten and get a result almost instantly. By cancellation we can even lose the exponent by expanding to 10x4x4/4=40. Looks more complicated written out but the only maths needed is to take the 4 and put a zero after it
40!!!✌🏾😌
I dud this in my head and got it correct. Yay!
Counted by 5 using fingers 16 time divided by 2=40?
Solved in my head at the thumbnail, the answer is 40.
No problem solved in a few seconds, but then I'm an old timer when i was at school we we taught properly
5”40
I got 40 and it took me around one minute 😅
5 x 8 = 40. Exactly!
Yep i can, i appreciate the quick brain teaser
40. Got it right first try!
Yes I can. I did.
Lmao “we thank her…”
I got 40 before opening the video.
How about a third way 5/2= 2 1/2 X 16=40
5*16/2
80/2
40
I got the right answer but only because of what I have picked up off this channel.
As someone who considers himself a nomophobe, I came to the right answer five seconds after seeing the video thumbnail, did i cured ?
I'm 73 these problems are fun doing math in my head got me in trouble in school all the time but I did it anyway!😊
The parentheses aren't needed, as multiplication/division is done left to right.
Parentheses are good for making the assumptions explicit.
45 - I see what I did wrong. I multiplied 5 X 16 wrong
Many of us redistributed it to 10 X 8. I like ten times any number for mental math.
The answer is YES and 40. ;)
Fourteen minutes to explain a order of operations simple equation? Four or five minutes at the most.
The parenthesis are not serving any purpose other than to confuse those not familiar with mathmatical heirarcy.
My grade. Went from D- -tp D+
40.
40. Piece of cake.
Easy peasy.
Lemon squeezy.
40 by piecemeal
40🎉
c) 39
😂
🙂
Have you played Nerdle?
Forty
Half of 160 divide by 2 is the way my brain saw it. 40 yea!!!!
yes i can. 40
I think i got it right when other person said an answer that was mine
40....
I did 160 / 2 / 2 = 40
40...?
I get 40 pretty quick.
did it in head...5 seconds
40 it is...
(5×16)÷2
=80÷2
=40
5 x 16 ÷2=40
one really has to be a dummy not to be able to do this in your head, but not everybody has a math mindset.
PEMDAS 40
(5 x 16)/2 = 40
But with "/", parentheses might be needed to avoid confusion.
40 is the answer
IF 5x16 escapes you for an immediate answer, just multiply 16x10 and ÷ by 2.
THAT ....... _should_ be...... nearly instantaneous.
This is not about being smart, or being quick witted.... or even mathematically inclinded......it's about memorizing the multiplication table(and, being able to recall it at will, lol), .....and knowing the rules for calculating. Still good for old brains tho, lol
I did 5x16 same way
@@Serisky621 .....and , the good news is, we both now know what 5 x 16 = right away, lol.
The answer is 40.
40?
40 in a few seconds
The long-winded PEMDAS lesson wasn't needed other than to explain that exponentiation comes before multiplication.
5×4²×½ = 40
Yeah. There is no division. It's an illusion.
There was division. You just converted it to multiplication. Unfortunately, there's too much division between people in the world. LOL!
8 times 5= 40
I got 40 on paper
It‘s 40
80/2=40
It's 40
A bit bleeding obvious ?
In my head 5 sec
40… rather easy.