Addition of exponents disconnect

August 2015Look at pp. 269, 272, 273, 275, 277In summary, the given example from the TEAS study guide contains an error in the third line where (10^4 + 10^4) is simplified to 10^4. The correct step would be to combine the terms inside the parentheses and then multiply by the common factor of 10^4, resulting in (35.709 + 5.789)*10^4. However, the final answer of 4.1498*10^5 is still correct. This error may cause confusion for students learning scientific (exponential) notation.
  • #1
dymand68
21
0

Homework Statement


(35.709 + 5.789)(10^4 + 10^4)
=41.498 * 10^4



Homework Equations


this is an an example given in my TEAS (standardized skills test) work book/study guide...is it accurate? i don't know why (10^4 + 10^4) = 10^4 after the simplification



The Attempt at a Solution


 
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  • #2
dymand68 said:

Homework Statement


(35.709 + 5.789)(10^4 + 10^4)
=41.498 * 10^4



Homework Equations


this is an an example given in my TEAS (standardized skills test) work book/study guide...is it accurate? i don't know why (10^4 + 10^4) = 10^4 after the simplification



The Attempt at a Solution


That is not standard scientific (exponential) notation. Are you sure it wasn't written like this?

(35.709*10^4 + 5.789*10^4)

That would be more standard. Written as you show it, it is indeed wrong, or at least confusing.
 
  • #3
the total given example:
(3.5709*10^5)+(5.789*10^4)
=(35.709*10^4)+(5.789*10^4)
=(35.709 + 5.789)(10^4 + 10^4)
=41.498 * 10^4
=4.1498*10^5
 
  • #4
dymand68 said:
the total given example:
(3.5709*10^5)+(5.789*10^4)
=(35.709*10^4)+(5.789*10^4)
=(35.709 + 5.789)(10^4 + 10^4)
=41.498 * 10^4
=4.1498*10^5

Weird. I've certainly never seen that notation, and IMO it shouldn't be used. If the 3rd line were:

=(35.709 + 5.789)(10^4)

then I would be okay with that. But not the way they wrote it.
 
  • #5
dymand68 said:
the total given example:
(3.5709*10^5)+(5.789*10^4)
=(35.709*10^4)+(5.789*10^4)
The step below is wrong. Both terms above have a factor of 10^4, so the next line should be = (35.709 + 5.789) * 10^4.

It should be noted that 10^4 + 10^4 = 2*10^4, and this should further convince you that the next line is wrong.
dymand68 said:
=(35.709 + 5.789)(10^4 + 10^4)
=41.498 * 10^4
=4.1498*10^5

Whoever worked the example got the correct answer, but two steps along the way are incorrect.
 
  • #6
thank you, fwiw-the source is
ATI, Assessment Technologies Institute, LLC
Test of Essential Academic Skills Pre-Test Study Manual, edition 3.0
 

What is the "Addition of exponents disconnect"?

The "Addition of exponents disconnect" is a mathematical concept where adding two exponents with the same base does not result in the expected sum.

Why does the "Addition of exponents disconnect" occur?

This occurs because the rules of exponents state that when multiplying two exponential terms with the same base, the exponents should be added. However, when adding two exponential terms with the same base, the exponents cannot be added and must be multiplied instead.

Can you provide an example of the "Addition of exponents disconnect"?

Sure, let's look at the expression 2^3 + 2^4. According to the rule, the exponents should be added resulting in 2^7. However, when we expand the expression, we get 8 + 16 = 24, which is not equal to 2^7.

Is the "Addition of exponents disconnect" a common mistake?

Yes, it is a common mistake made by students when first learning about exponents. It is important to understand the rules of exponents and when they can and cannot be applied.

How can I avoid making mistakes with the "Addition of exponents disconnect"?

To avoid making mistakes, always remember the rules of exponents and be careful when adding exponential terms with the same base. It is also helpful to practice and review problems using exponents to reinforce your understanding.

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