Should I let my 10yr old , and 7yr old grandsons beat me at chess?

Thank good that we are talking about chess and not boxing, some people here would probably knock the light out of their kids in a light sparring because "no pain, no gain". 

OP, play with handicap and be clear about it with them. Either material or some extra rules for you (no castling, not capture on obvious blunder etc). Lessen the handicap with time as they get better and do play them with full strength from time to time.

It's easy for people with no kids to be certain about how to raise them . I forget who said it but I remember the quote "Once I had 3 theories about child raising and no kids. Now I have 3 kids and no theories."  My 3 dont play chess but they are expert (class V+)  WW kayakers. They learned by positive successes and ice cream afterwards.  -Bill

Ok, i did listen to you. Now try to convince the Maths teachers to go all wrong doing calculations in the blackboard for the kids to be all at the teacher's level faster.

Nowadays, when kids don't have other kids to play chess with, they have computer surrogate partners, like the excellent ones here at chess.com. We are not in the 1970's anymore, when I started playing chess.

Wrong comparison, you are talking about explanations of a concept not implementation of it. But giving students to hard questions which they can't answer is a great way to make kids hate math, which is why teachers try to adjust both questions as well as individual explanations to the level of their students.

Interesting question. I can't speak to chess specifically but I remember being annoyed as a kid when adults used less of their power in board games, arm wrestling etc. Loosing can still mean you had great fun and if you can teach your child that, when they eventually win it will be a lot better!
Anecdotally in wrestling I had a lot of success from this method - to always value learning and getting better from a realistic view. That is the joy!
Later in wrestling it became popular to give all the kids medals and to raise the arm of both kids. My friends younger brother got to learn wresting rag-dolling around adults, later when he got confronted with reality he quit.

Not the same thing.  Would you have taken them to class I river segments all their life and then let them try a class V?  I'm guessing no.

The modern age is a tug of war, with social convention and wisdom turning further and further towards giving kids a cocooned childhood and then releasing them into the wild...but like anything else, moderation is called for.  Extremes are bad, mmmkay?  Letting anyone at any age win chess games 85% of the time and then giving them ice cream is a method that will produce slow progress and lots of hurt feelings later when reality sets in.  It sounds good, as a narrative, though.

I think you should play with your right hand your first game and play with your maximum strength,  Then you should announce the next game you are going to play with your left hand, which is weaker, and then make slight errors hand hang pieces in a way that if they notice it, they will have an advantage. 

Keep it going for as long as they don't notice what you are doing. 

That said, chess involves an opening, a middle game and and end game.  If you keep winning the middle game, your kids won't get any experience in end games.  If you decide to beat them up route, I would suggest doing end game and mate puzzles after your games, just so they have some victories and end game knowledge.   

oh good point

1. Your kids are beginners
2. They are not hooked on chess yet, i.e. they could still lose interest rather easily
3. You are much better than them
4. In the future you would like to see them playing some competitive chess, getting a FIDE rating, reaching a decent level, etc. 

@GaborHorvath : this is true for many beginners, not only kids. While there are some people who really like the "lose 1000 times to become better" attitude, there are probably as many if not more people who prefer to have fun by winning and not only by struggling. That's why gamification works, a lot of people like to have small achievements early on instead of a grand prize at the end of their journey. 

As long as we raise the difficulty/lower handicap progressively it shouldn't be bad and crippling as some imagine.

@GaborHorvath - Thanks for the perspective. Not how I approached it before, but if I get the chance to teach beginners again then I will try your method and see how it works.

@Dmfed - Good job suggesting the answer might be different depending on the personality of the beginner. It has been missing from the discussion so far. (Mostly missing - llama36 hinted at it.)

It depends on you

Be kind to them if they insist, but I still just think you should go easy. Times were different in the past

I disagree. As a kid, i would feel horribly dissapointed whenever dad let me win. It would ruin the experiance for me. I would have prefered to just lose rather than win, knowing that dad let me win cuz he felt sorry for me and knew i didnt have a chance.

I don’t how relevant this may be… my Mother taught me how to play rummy and she never let me win a single game. I still loved playing rummy with her regardless. When i wasn’t sure what to do or she could see i made a mistake, she would ask “are you sure you want to do that Wits-end?” Sometimes she would say “show me what you have in your hand” and then teach me. I never felt discouraged, abused, or looked down upon. One day i won, but not many after that. She was still better than me. I’d give almost anything to play a hand with her again. 

No.

And then it is also important to remember that most people are not just one thing and don't have just one motivation. They probably need a good mixture of different roles to really enjoy an activity to the fullest. A mentor who teaches, a friend on the same level and some newbie who they can teach themselves as well as having an impossible goal, a relatively close rival and maybe someone a bit weaker against whom they can show off all their might.

Often, one person can play multiple roles and if they play in a club or with friends it is easy to fill. On the other hand, if grandpa is their main or even only source of chess it would be good to know what is their motivation, wants and needs.

But overall most tips in this thread are rather same-y, even if people are for or against giving in. Be honest, mix cooperation and competition, try adapting to their level and gradually raise it. 

I think you should let them learn, not win.

So if you can give them a winning position sometimes, that would be nice.

But no, they should learn that chess is hard. It will have them push themselves. Hold your ground and resist mommy's sweetness. But never value chess above her either

it probably depends whether they are male or female too. Those two genders react differently to those kind of situations. For example boys feel challenged and want to do anything to win, while girls feel more discouraged when losing I guess.