Questions misinterpreting E as e

[kiratskitizing]

There appears to be an issue when it comes to using E and e. Here are the examples given to me for reporting.

Replication:

1. Add a stack question

• Question name: Test
• Question variables: ta1:?;
• Question text: [[input:ans1]] [[validation:ans1]] e
• Specific feedback: [[feedback:prt1]]
• Question note: {@TA1@}
• Input: ans1
• Input type: Algebraic input
• Model answer: ta1
• Forbid float, require lowest terms, check the type of response: All "No"
• Student must verify: Yes

2. Preview the question: Type e

• 
• e is represented as e

3. Preview the question and in the textbox type: 10*e

• 
• 10e is represented as 10e

4. Preview the question and in the textbox type: 10e10

• 
• 10e10 is represented as 10 x 10^10

5. Preview the question and in the textbox type: 10E10

• 
• 10E10 is represented as 10 x10^10, which is the confusion

6. Preview the question and in the textbox type: 10/e

• 
• But 10/e is represented by 10/e

Expectation: e should be for the natural number when multiplying, as seen with division, and E should be use for exponent.

[sangwinc]

Thanks for raising this issue @kiratskitizing. People really do use 7e9 as correct syntax for 7*10^9. Indeed, when we look at the international standard such as BS6727 (1987) we have both E and e used for the exponent mark. This is also acknowledged here: https://en.wikipedia.org/wiki/Scientific_notation

Extract from BS6727:

---

5 Character set

5.1 Description

The character set for the representation of numerical values shall be a sub-set of the ISO 646 coded character set.

5.2 Syntax

The following syntatic objects are defined using the method of syntax specification described in Annex A.

a) digit = 0/1/2/3/4/5/6/7/8/9
b) sign = +/–
c) decimal-mark = ,/.
d) space = SPACE
e) exponent-mark = E/e

---

We also have some test cases confirming this behaviour e.g.
https://github.com/maths/moodle-qtype_stack/blob/master/tests/fixtures/inputfixtures.class.php#L110

I've just checked, and even with "insert stars for implied multiplication, spaces, no user-functions and assuming single character variables" the students input 7e9 is a float, not 7*%e*9.

There is a genuine ambiguity here, and I understand why you might ask for this! We just made a decision in the other direction, sorry. This isn't a bug and I don't think changing the behaviour would be sensible. Indeed, I personally think students need to interact with computers and understand the both "e" and "E" are the exponent mark.