Merge pull request #38076 from xymostech/master

Fix the MgCl_2 weight calculation
Hide sliding window in visualizing derivatives when user clicks 'no solution'

Test Plan: Tested locally with hints & combinations where user clicks no solution when there is a solution and vice versa.

Reviewers: alpert

Reviewed By: alpert

CC: eater

Differential Revision: http://phabricator.khanacademy.org/D1032
Use type=number on exercises with multiple inputs.

Test Plan:
local, Chrome/OS X with local hack to bypass touch detection in
utils/answer-types.js

Reviewers: tom, eater

Reviewed By: eater

CC: stephanie, alpert

Differential Revision: http://phabricator.khanacademy.org/D1027
Use type=number on more exercises with multiple inputs.

Summary:
Use type=number on Adding and Subtracting Complex Numbers.

Use type=number on Adding and Subtracting Decimal Word Problems

Use type=number on Adding Vectors

Use type=number on Angle Addition Postulate

Use type=number on Angles of a Polygon.

Use type=number on Area 1.

Use type=number on Area of Parallelograms.

Use type=number on Area of Squares and Rectangles.

Use type=number on Area of Triangles 1.

Use type=number on Areas of Trapezoids, Rhombi and Kites.

Test Plan: local, Chrome/OS X

Reviewers: tom, eater

Reviewed By: eater

CC: stephanie, alpert

Differential Revision: http://phabricator.khanacademy.org/D1030
typos (Fixes #37436)

Test Plan: none

Reviewers: tom

Reviewed By: tom

Differential Revision: http://phabricator.khanacademy.org/D1035
Fix freethrows independent_probability hints

Closes #38239.

Auditors: eater
Make wording a little more exact

Closes #38160.

Auditors: eater
Clean up minor nits.

Summary:
add line ends before EOF
data-form integer is redundant when decimal is specified

Test Plan: none

Reviewers: tom, eater

Reviewed By: eater

CC: eater

Differential Revision: http://phabricator.khanacademy.org/D1039
Make comment nicer.

Test Plan: none

Reviewers: emily

Reviewed By: emily

CC: tom, eater

Differential Revision: http://phabricator.khanacademy.org/D1044
"integer" is a data form, not a data type.

Summary: Fix Telling Time exercise.

Test Plan: locally

Reviewers: tom, eater

Reviewed By: eater

Differential Revision: http://phabricator.khanacademy.org/D1047
Target type=number inputs in CSS as well.

Test Plan: locally

Reviewers: eater

Reviewed By: eater

CC: tom

Differential Revision: http://phabricator.khanacademy.org/D1043
Change "percent" answer type to interpret answer key as a decimal; accept percent in independent_probability Fix #37553

Test Plan: Ran `grep percent exercises/* | grep data-forms` to find all exercises using the percent data-form and tested several questions of each such problem type

Reviewers: alpert

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D1046
Use integer data forms on All the Exercises!

Summary:
Okay, not all of them. But a lot of them.

Use number field on Changing Decimals to Percents.

Use integer data form for Converting Between Point Slope and Slope Intercept.

Use type=number fields on Converting Between Point Slope and Standard Form.

Use integer data form in Domain and Range of a Function 0.5.

Use integer data form in EQuation of a Circle 1, 2

Use integer data form on Equation of an Ellipse.

Use integer, decimal data forms for Inscribed Angles 1, 2, 3

Use integer data form on Matrix Addition and Subtraction.

Use integer data forms for Matrix Dimensions.

Use integer data forms on Matrix Transpose.

Use integer data forms for Measuring Angles.

Use integer data form on Multiplying a Matrix by a Matrix.

Use integer data form on Multiplying a Matrix by a Vector.

Use integer, decimal data forms on Multiplying and Dividing Scientific Notation.

Use integer, decimal data forms on Multiplying Complex Numbers.

Use integer data form in One Step Equations.

Use integer data form in Perimeter 1.

Use integer data form in Perimeter of Squares and Rectangles.

Use integer data form in Pile Patterns.

Use integer, decimal data forms in Plugging in Values.

Use integer data form for Quadrilateral Angles.

Use integer and decimal data forms for Range of a Function.

Use integer data form for Reading Bar Charts 1.

Use integer, decimal data forms for Reading Line Charts 1.

Allow decimal data form for Reading Pictograms 2.

Use integer data form for Reading Tables 1,2.

Use integer, decimal data forms on Scientific Notation.

Use integer data form in Simplifying Expressions with Exponents.

Use integer data form in Solid Geometry.

Use integer, decimal data forms with Square Roots.

Use integer data form with Square Roots 2.

Use integer data forms with Scalar Matrix Multiplication.

Use integer data form on Telling Time 0.5

Test Plan: locally

Reviewers: tom, eater, stephanie

Reviewed By: eater

Differential Revision: http://phabricator.khanacademy.org/D1048
Don't ask questions with -1i as part of the answer

People were typing [-]i instead of [-1]i. This is a hacky workaround.
This also makes [ ]i equal i instead of 0i.

Fix #38028
First pass at creating a new extract-strings.py script for our i18n efforts.

Summary:
This is a simple script that's able to extract strings from the Khan Exercises .html files and generate a .po file.

I haven't evaluated how accurate the results are yet - and I've found at least one major issue which I'll resolve tomorrow, namely that elements inside of banned elements (like `<code>`) are still being picked up.

Test Plan: Run `python build/extract-strings.py`. You should end up with a file named `exercises.po` containing a number of translatable strings.

Reviewers: csilvers

Maniphest Tasks: T340

Differential Revision: http://phabricator.khanacademy.org/D1058
Set arcanist project in .arcconfig to tag reviews

Notably, this lets people make Herald rules that filter on repository.

http://www.phabricator.com/docs/phabricator/article/Arcanist_User_Guide_Configuring_a_New_Project.html

Auditors: eater
Changed names and mass numbers for some elements
Merge remote-tracking branch 'khan/master'
Merge pull request #38490 from epicfaace/master

Periodic table updates
MathJax the whole range expression

Auditors: stephanie