But to be guilty of the offense in Idaho, a person must willfully ingest the human body part. Being tricked into the act doesn’t count. However, this prank likely runs afoul of federal food tampering laws. It could also be classed as an assault, the same as contaminating a person’s food/drink with bodily fluids.

Aren’t those all still based on basic addition and multiplication? If you don’t know 2+2=4, breaking down 2*3 into 2+2+2 doesn’t help.

Memorization is about speed. Knowing 3*4=12 is much faster than 3+3+3+3.

We use an electronic timer. Started with adding single digit numbers. He needs to provide answers before the timer goes off. Right answer adds a dime, but wrong answers or no answer before time expires subtracts a dime. Identified the numbers he had trouble with. We play until he’s taken a couple dollars from me. I always let him win a couple dollars to keep up the interest. Lowered the time until it was down to a second.

Most math is learning and applying a technique. But there is no technique or formula for adding/multiplying single digit numbers - it’s all memory. That’s what I did with my grandkids, and it frees them to learn the techniques without struggling with the basics.

I played math games with my grandkids for pocket change. Get it right, I give them a dime. Get it wrong, they give me a dime. It’s cost me at least $100, but they can now accurately do basic math in their heads almost instantly. My grandson went from failing math to excelling in the subject. He can do math faster than using a calculator.

If the fan blew across an airfoil aligned perpendicular to the axis of the boat, it can definitely generate thrust. The top of the airfoil will develop a lower pressure than the bottom, and the difference in pressure causes force that moves the boat. It’s just way more efficient to use a fan to push the boat.

Assuming the chance of either sex is equal, this problem can be broken down into multiple cases. The first is that there are two unseen kids in the house. What’s the probability they are both boys? 1/4. Now the door opens and you see two boys. The probability both are boys is 1/1. But if you only see one boy, the problem simplifies into the probability of a child being a boy. One of the probabilistic events postulated in the original problem is fixed at 1. So the answer is 1/2.

Think of it as the two coin flip, except one coin has two heads. That simplifies to a one coin flip.