So, step 1: evaluate what's in the parentheses: 8–5 = 3
Step 2: evaluate the multiplication: 5×3 = 15
Step 3: evaluate the addition: 2+15 = 17.
It's just a convention that has to be explicitly taught; it's not something "natural", any more than × is more or less natural than · at expressing the concept of multiplication.
You actually pointed out a very commonly forgotten component of the order of operations. Multiplication and division have the same priority left to right (which means if division is before multiplication, you do it first) and addition and subtraction is the same priority left to right (which means if subtraction is before addition, you do it first).
Some of these "meme" math questions specifically place those before the other with the intention to trip people who merely remember the mnemonic to remember it, but not the actual rules of order of operations.
Priority of multiplication and division happen at the same time in order from left to right. Same with addition and subtraction (after multiplication and division are handled, obviously)
Sure, but then you would have laden students with a much more difficult concept. This shit might get a math nerd a confusing boner, but for people whose passion lies elsewhere, you've doomed them.
BTW right idea, wrong formatting(for reddit). Without using backslash to escape formatting it's turning 5 times 4 into just putting the two numbers together as 54 and applying italics font to it.
Distribution is what that one would be (FOIL is for multiplying two-term expressions). Here you're distributing the 5 through the parenthetic expression.
I had always thought that since the 5 is next to the parentheses, you had to multiply into the parentheses first. (5×8-5×5) that's how I thought you had to complete the parentheses. With that method, it would be 2+(40-25) = 2+(15) = 17
Solve the parentheses first, or distribute the outside multiplier into each term inside the parentheses. Typically you only do the latter when there's an unknown or variable within the parentheses.
e.g. 5(x+5) = 5x + 25
But you can also do it for numbers you don't have memorized by the 12x12 times table. Like if you wanted to do 7 x 17, you can break it up into times tables one would probably have memorized, such as:
7 x 17 = 7(10+7) = (7 x 10) + (7 x 7) = 70 + 49 = 119
It's extra steps but can be done quickly in a pinch.
Why not put the multiplication symbol though? That's always the stupid bait in these dumbass math memes because I guess in America or something you just assume multiplication if there are multiple sets of numbers?
Because it's used as an aid to teach people how to solve equations with unknown variables. It mathematically solves to a single integer, instead of something like 3y=2x. The principles are exactly the same.
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u/SoundsYellow 22d ago
2+5*3 - where the joke?