Solve this equation
- Thread starter ISUCyclones2015
- Start date
It was mentioned earlier, but the whole "implied multiplication precedence" phenomena is the main culprit for the different answers. And it's part of the reason why calculators throw different results. While 8 / 2(2+2) should be the same as 8 / 2 * (2+2), the programmer potentially coded is such that 2(2+2) gets done first. It is why my old T1-85 treats it as both 16 and 1 depending on whether you put the multiplication symbol in between the 2 and the parentheses or not. My phone and computer, on the other hand, will not even allow it to be input without the symbol automatically being inserted, thus eliminating any ambiguity.
If it makes anyone feel better I learned PEMDAS 40+ years ago while in school but my kids learned PEDMAS. But the person who broke it down like this is correct:
Level 1: Parentheses first, inside to outside
Level 2: Exponents next
Level 3: Multiplication and Division (same level), left to right
Level 4: Addition and Subtraction (same level), left to right.
Whether it is multiplication indicated by an x, a dot, an asterisk, or no symbol at all it is still multiplication and still governed by this rule. The same goes for division indicated by a slash, a horizontal line* or the division operator that looks like a colon and a hyphen typed over each other. Same rule.
______________
*You have to be careful of the horizontal line because whatever is on top of and below the line can change the grouping of what is being divided essentially acting as parentheses. The length of the line matters:
The formatting here won't let me show this entirely but if
2+16
8
is written with a line completely under 2+16 and over the 8 that is (2+16)/8 and would be 18/8 or 2 2/8 or 2 1/4. If the line is only under the 16 and over the 8 that is 2+16/8 and would be 2+2 or 4.
Level 1: Parentheses first, inside to outside
Level 2: Exponents next
Level 3: Multiplication and Division (same level), left to right
Level 4: Addition and Subtraction (same level), left to right.
Whether it is multiplication indicated by an x, a dot, an asterisk, or no symbol at all it is still multiplication and still governed by this rule. The same goes for division indicated by a slash, a horizontal line* or the division operator that looks like a colon and a hyphen typed over each other. Same rule.
______________
*You have to be careful of the horizontal line because whatever is on top of and below the line can change the grouping of what is being divided essentially acting as parentheses. The length of the line matters:
The formatting here won't let me show this entirely but if
2+16
8
is written with a line completely under 2+16 and over the 8 that is (2+16)/8 and would be 18/8 or 2 2/8 or 2 1/4. If the line is only under the 16 and over the 8 that is 2+16/8 and would be 2+2 or 4.
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