For the 6 year old's 100th day of school we sent in 100 Legos.  Ten rows of ten, Lego and math combination win.

6 year old learning about the speedometer on the car.
6 year old: So mom, what are the numbers on the dial for?
Me: Well, that is the speed limit, on this street it is posted ‘40 mph’ and you as the driver have to make
sure you don’t go faster than that by watching the speedometer, or else a policeman can give you a speeding ticket.
6 year old: Mom, what is the speed limit on the high road (his word for interstate)?
Me: 70 mph
6 year old: But the speedometer goes to 150 mph, what road can you go up to that on?
Me: No roads really, the highest speed limit I have seen is 70mph.
6 year old: That doesn’t make any sense, why would they make the dial go to 150 mph if you are only allowed to go 70mph?
Me: I don’t know, that is a good question about the design.

2 good ones from the 6 year old today: 
AM Win: Brushing teeth this morning. 
Me:It's the 8th, an even day, yor brother gets to brush his teeth first. 
6 year old: The 8th is even, 9th is odd, 10th even... Oh...mommy, I get it... if you count by 2's you get the even numbers! 
Me:Yes, great job figuring that out!  

PM Win:  Me: What did you like best at school today?  
6 year old: We learned how to draw a cube and a cylinder, it was cool. 
Me:  Yes, that is cool!

3D geometry sketching.... engineering mom win.

This six year old's and my first attempt at a ramp for the remote control truck from his aunt to jump out of the doggie door was not successful. 
Although it was just an impulse use of a big piece of cardboard I was getting ready to throw in the recycle bin (failed under weight of truck, need to use wood or support bracing).  We will put some thought and design into a proper dog door truck ramp soon.