Sudoku. Lesson 13 Sudoku There is only one place it can go.

sometimes you'll notice that probably I've made a mistake or I missed something and that happens to everybody and you'll be amazed at how you'll see the more of that as we go further into the advanced level because if I've had a class and I had two people start a puzzle the same puzzle they go in a different direction just because somebody missed a step or didn't see something but they finish up with the same answer usually in the end so when you're stuck we're going to give you some suggestions on what to do and one more thing just one extra number will be enough for you to finish the puzzle so let's start on this first lesson which is called there's only one place where that number can go it can be a could be a column it could be a row or it could be a block so let's get started here we go I'm going to show you the same procedure as we normally do step by step once well we have a 1 in the bottom here one in the middle here this has to be on the top of this block we have the block the blocks are made up of top middle and bottom top middle and bottom top middle and bottom and we're going to go the horizontal route to there's only one two three there's two threes one in the middle one in the top this one goes in here as soon as I do that I notice that in this block we've only got one number left if I count up one two three four it's a six that's missing so we put that in and that gives us two sixes top a middle therefore we know that a six has to go there because there's a six there you can't put it there seven oh six is where we're up to fours there's only one four fives there are two fives one on the top over here one on the bottom of this this particular block there for the five in this block where there's no five has to be in the middle so we put two little fives there and we look down to see if there's a five down in here whoops there's no fives here so we keep it as two little for Heights sixes we've done seven is three 7s is the top or bottom in the middle move on eight there's two eights or there's three eights is the middle a bottom and a top that's good nines we have one nine and it can go many places so we leave it let's go now to these three blocks horizontal once we had two ones 1 here and a 1 here therefore there's got to be a 1 in here and a 1 there and I'm going to put the ones in and look down there's no one so leave it to this one too so leave it 3 there is 1 3 so leave it force there's only one for we're looking for a 1/4 here and 1/4 and one of these two we're looking for a number that's in 2 out of the 3 blocks there was only one so we leave it fives there's a two fives here there's a bottom one here there's a top one there therefore it has to be in the middle of this block in this row so it's 5 and 5 and this is a matching pair and that's so powerful as you'll see a particular ly in our next lesson the matching pair means that no other little numbers can go there it's only one of those two numbers sixes we have three sixes middle top bottom sevens only one seven leave it I can't see something but down the road we'll show you how to do that eight there is only one eight nine there's two nines as a nine here in the middle of the nine in this block and the top there's a nine there needs to go in this block on the bottom Middle top this has to be on the bottom so it's one of these two nuts look up to see if there's a nine is it a nine up here no so it stays as two little notes ten oh no we don't go any fast now do be well just family fun okay now we'll go to this one and this particular horizontal set of blocks is where I want to show you the new technique to to use when you're sort of got to the stage where you're stuck and you don't know where to go next try this out it may not always work but it's sure not need to know what to do I'm going to say take a particular column actually and you use column number six one two three four five column number six and I'm going to see if a one can go in there somewhere well let's look in this block the cell that can't be a one because of that one in this cell it can't be a one because of this one in this cell it can't be a one because of that one in this cell it can't be a one because there's that one here and in this cell you can't be a one because of that one so the only place everyone can go is there that's called only one place for a number to go very handy little technique to use fine let's finish off the horizontal lines here we've got three ones now no two no twos threes we've got three three so again with it we're done four there's only one for you can go in many places so let's leave it fives as one five only one five you can go in many places over here leave it sixes there's only one six so the same again seven there's only one seven it can go in all these places too much information too many spaces to put it otherwise it gets very cluttered with little numbers and becomes confusing later on and eight only one eight so a no no nines so now we're ready to go to the next step where we do vertical columns by the block this block of this block this block in this block then these blocks okay number they will do a 1 the ones are already there fantastic 2 we have a 2 here we have a 2 here and therefore we have to put a 2 here and a 2 there there's no tools along here so it stages to small tubes threes well we have the threes already we have a middle and this is called left left center right whereas this is called top middle bottom okay that's my breviary for those of you have taken my first course you understand all these very important procedure to take to do every time you do a puzzle okay we're up to force we've got the fourth we have a 4 we have a 4 and a 4 a right a left and a center and fives we have two fives we have a five here and the left of five on the right and two fives have to go in here here we go two fives there's no 5s along here so leave it sixes there's a six here there's a six here our Center a right it has to be down in here and that's the only place that can go and that becomes a matching pair follow that okay sevens we have a seven well in this block it can do in two two two spaces we can put a little seven there and a little seven there that means that if that's the case left center right so this is going to be a seven seven very good eight we only have one eight let's leave it nine we have mmm we only have one nine let's leave it there's too many spots for it fine now we'll go on to this set of blocks we have ones well we don't too much information we don't know whether could go there it could be there there there there there or there we don't know leave it twos when we have one two and you can go all over here so leave it actually no actually you know just notice something because of that - it could go either there or it could go there hmm see ya yeah that's right threes threes well this is important to teach here we have a left there we have a right in this block we don't have a three and it has to go there so we have right center left this pattern is the theming set of vertical blocks that's the three now why can't it go there the reason is simply this if you have a matching pair no other number can go there we don't need to put other little numbers in there otherwise it becomes very messy in Treasury for us there's no force and will go on to fives there's several places for fives that's not going to help us six well this is interesting it can go in two spaces we have a right Center it can go over here or here sevens we have two sevens and we have three sevens we're done eight well an eight could go here or here if it ain't nurse is important if an eight goes here or here that means we have a center we have a right it can go here as well a be a six eight and a six eight which makes them a matching pair very handy oh now let's go to nine so we only have one nine and it can go all kinds of places so we'll leave it at that let's now go we've done the nines now we're going to go to this column ones they're all there twos no twos threes well we have a center we have a left so there has to be on the right here and it can either go there or there but if I look across here there's a three already so the only place it can go is there so we've done the threes now fours with no force there at all fives we've done the fives right let us enter left sixes when we've done the sixes right left center 7s well we can have a seven in two places we can either be here or here but I want to show you a little trick here if I put the seven there there's no place for it to go there remember we covered that before if that's filled up they can't have a seven there so that means the only place of seven can go because he you have right center left there's no room for it there so it can't be there it has to go here seven if that's the case we know that we have a seven in here and a seven there moving right along eight well we've got the eights already and now we're to the nines well there's only one nine and so I'm going to leave it there for the time being because what I want to do now is to look for rows and columns that have only got two or one or two cells left that are empty and we'll do some matching pairs let's take for example or this one here this is this is a block that has a matching pair now what is the number that's missing I think it's a two is one of them one two three four it's of two and a four to four there you go they're a matching pair now does that match mean anything in here two and four - and what's look at this look we've got a two across here so what does that do that cancels out this two because we've already got it - so that becomes a four and therefore this becomes a 2 now that's very good we're again making some progress now that block is full here's a row that does only have two left and we can't have a seven little seven there because that seven is there now but what is missing let's count one two three as a four missing is that right a four is missing this is interesting this is the four and and eight and four and and eight are missing now let's look and see the ramifications of that we already have a four in this block therefore that cancels out that four and it becomes an eight if that becomes an eight this becomes a four very good now here's another row that's only got two left in it what's the two numbers that are missing one is a two missing three four five six seven eight it's a nine - nine - and a nine matching pair again is there two down here or nine down there is a two or a nine down here no we have to leave it okay let's move on to another place here we have quite a few places there's only two left in here but we've worked on that one already there's only two numbers in here left in this block and I can see what's going to happen maybe you can already - what's missing in this block it's a seven and a nine if you count through you'll come across a seven and a nine that's missing now let's look up and down if we look up here what do you notice there's a seven there so that cancels out this seven this becomes a 9 so we have 9 there and a7 there what's the ramification of that let's have a look here is a seven left here's a seven it has to be on the right that's all correct that's good what about the nine nine nine one of these is the nine so we now have another matching pair because there's only two left in that in that row now there's only two left in this row what is missing one two three four five six seven eight it's an eight that's missing there's a nine there so we have seven eight whoops that was first not very good eight I'll just do that again seven eight and this is the seven eight and it's a matching pair as well now look at this is interesting because next lesson I'm going to talk about this this block has got absolutely it's fascinating it's got three matching pairs that can happen it can happen in a block it can happen in a row you can happen in a column fine we're pushing on right along now what's missing in which which which areas here now I'm looking to see if we can look into now one of the S an idea one of the things we learnt earlier in the course was when you have three left in a row like this in a block you can work out water then what notes are missing what numbers are missing rather so let's see what it is it's a one two is missing and you can't be there so we have to put a two there and there's a two there two one two three four is missing so we put a four there okay and a four there so we have two four nine that are missing here's a two so it's a four nine in here and I've underlined it because that's the only two numbers that can go there because these two four nine have to fit in here somewhere and this one's got a nine so it's two four and this one is a two that's going to be a two there's a four here so it's a two nine that's good so that will really help us we're down the road somewhere I'm sure it will we'll keep watching let's have a look at some other things here or look at this line here see that row there's only one missing isn't there if there's only one missing and happens to be the little number eight becomes the rule eight one two you count it up it comes to eight so what does that do it gives us an eight over here and that fits you know you're on the right track and now let's look at somewhere else where we've only got a few left here we have a six eight six eight we have oh yeah I'm going to have two left in this row what was it again let's check it out one one two there's the two missing so it's a to seven at two seven matching pair Wow now because that is a matching pair and there's now only two cells left we can actually put another matching pair in there because there's only two cells left in this one so it's one two three it's a four and five six seven eight it's a four nine I think for nine and a four nine great now we're getting closer in this particular let me see now where are we let's see which is the best thing to do I'm going to now go outside the puzzle in this particular row we have got what a missing we're missing three numbers it's four six four we've kind of a four here look I've just noticed that you probably noticed it before I did that fault cancels out this four which makes that a nine if that is a nine therefore this becomes a four now let's look at the ramification of all that if that's a nine that's a nine we know we're in the right track there if there is a four there before there a four has to be here it can't be there because as the four already there if that falls out the middle and it's the center a right or four has to be over here okay now let's go back to what we just did here I put in a four down here is that right yes now put in a two and a seven Wow we've got all kinds of numbers here coming up we'll find them don't worry we'll go now - let me see now six six six six six where can we go next well let's try this this the top row we can go outside the puzzle if we want to it's one two and four just in case you can't remember it all you can put it out there let's just check that out there's a two here so it's a 1/4 that's for sure there's a 1 to 4 stay taken up so that's that's that's correct and here we have a two four two four two four two four well we've got quite a few things there now there's something I'm probably missing somewhere I'm just keeping looking looking forward here here let's try this column here there's three empty ones there the numbers are 2 2 9 and something else - 9 and something else let me see 1 2 3 4 5 there's a 5 missing there's a 5 and a 9 to 5 9 now we take that 2 5 9 and we look along here look here's a 5 9 2 has to go there there's nothing else that can go there so we're now crossed out the 2 we've got the 2 done now we're left with a 5 & a 9 okay well did you notice here this 6 cancels out this 6 watch this happened this is neat that cancels out this 6 note that means that this becomes an 8 this becomes a 6 this becomes a 6 + 6 6 this becomes a 6 top bottom middle over here this becomes a 6 this becomes a 2 well see what the power of the matching pairs very good now we have an 8 over here we can't have an 8 there now so that 8 is cancelled and that becomes a 7 and therefore this becomes an now that's interesting we're getting weaker really making some progress now in this we were going about the five nine in here if because we have a two here that cancels out this this two so that becomes a nine and therefore this becomes a 2 watch what happens here if that's a 2 this is cancel this 2 that becomes a 4 if that becomes the 4 this becomes a 9 see what these pairs can do for you very good if that's a 4 this becomes a 1 if that's a 1 this becomes a 2 Wow see the handiness of putting them in pairs if you can okay so therefore we're left with a 4 5 in here matching pair but if I look down look down here on this 4 or 5 there's a 4 down there so it can't be a 4 there so that has to be a 5 and this has to be a 4 ok and now we're getting somewhere if that is a 1 up there what's the ramifications so many ramifications happening now because of all our little pairs that we've got going all over all our mat and matching pairs here's the one that cancels out this one so that's becomes a 5 and this becomes therefore a 1 that becomes a 1 and now in this block we've only got one number left and I think it's a 7 1 2 3 4 5 no it says 5 it's a fire that's missing because the 7 is in here and there's that now you can check yourself is there a 5 bottom Middle top yes we're on the right track self checking those you go we're using tmb and LCR really does help you find mistakes that you've made quickly now this column has only got one left and I believe it will count it up 1 2 3 4 5 6 7 8 it's a 9 well what does that do over here watch what it does it cancels that 9 out that becomes a 5 and this becomes a 9 and we're getting pretty close to getting exciting if that is a seven here therefore that cancels that seven out so that becomes a two and therefore this becomes a seven and we can check ourselves out here we have a middle a top and a bottom that's correct poor boy we've only got one left fantastic and wondering what that is that's text check it out one two three four it's a five and we can just make sure that it's a rather top a middle and a bottom similar to what it was up on top and whoopee we've done a puzzle and now you've seen the technique and the procedures that I go through we can also show you much more in the next lesson so bye for now

Channel: Sudoku Guy

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Keywords: how to solve sudoku, sudoku lessons, sudoku for all levels, sudoku for beginners, sudoku for dummies. how to solve sudoku puzzles, instructions on how to solve sudoku, demonstrations of sudoku solving. brain fitness, memory practise, sudoku for seniors, sudoku for the frustrated, advanced sudoku strategies, spare time activity, fun with sudoku, simple sudoku, sudoku tricks and hints, Sudoku tutorials, Sudoku for brain fitness., sudoku, advanced sudoku techniques, Sudoku Guy

Id: E6RHrMe1RuE

Length: 22min 59sec (1379 seconds)

Published: Mon Feb 16 2015