There are two tricks to this one. The first is 1 × 0. But it’s mostly there as a distraction. Yes, 1 × 0 is 0, but that doesn’t affect anything else in the equation. The second, far trickier element is that the lines ending with 1 don’t have a + sign next to them. That means they should be combined with the following line.
I’m a sifter of a memorable shape,
You can eat a variety of me, but I can be toxic,
I can cause severe pain if you’re not careful,
And the action I describe could hurt as well.
Kidneys filter your blood and are shaped like kidney beans, which you can eat. Red kidney beans contains high amounts of phytohemagglutinin (quite the word, eh?) and can be toxic if not soaked and boiled. Kidney stones can be extremely painful and if a kid knees you in the stones, that would also be unpleasant.
What is the longest unscientific English word that uses every letter in the word exactly twice? For example, noon has two Ns and two Os, but it’s not nearly long enough.
Happenchance. There are two Hs, two As, and so on for all the letters in the word. The longest scientific word with the same property is probably esophagographers.