Algebra:  Quadratic Factorisation.

              Coefficient of squared term is 1.

Straight line graph formula

Calculate the functional value at a point.

Calculate the functional value at a point.

This exercise will help you rearrange a linear equation to find the value of a given variable

Factorising polynomials using the highest common factor

Simplifying algebraic expressions

A 'concept test'.  3 multiple choice questions about a graphed normal distribution curve modelling IQ data.

A demo of the match choices with answers part and its options.

No caculation 'concept test' on confidence intervals.  A single multiple choice question interpreting a CI.

A 'concept test' (no calculations) with 4 multiple-choice parts.

Calculate reactions and shear and bending moment at a point for an overhanging beam with a constant or uniformly varying distributed load.

True/false question type to assess basic knowledge of confidence intervals.

Modulus and argument of a single complex number $z=z_1/z_2$, where $\mathrm{Re}(z_1)=\mathrm{Im}(z_1)$ and $\mathrm{Re}(z_2)=-\mathrm{Im}(z_2)$.

Calculation of modulus, argument, multiplication by complex conjugate, given two complex numbers.

Characterise the cosh function as continuous, many-to-one, even, and find the limit as x approaches 1. Part of HELM book 2.4.3.

Given a linear or a quadratic function and asked whether it is continuous. Part of HELM Book 2.4.

Determine the forces in the pistons of a hydraulicly operated excavator.

No description given

End of chapter exercises for Engineering Statics: Open and Interactive 

Determine expressions for internal shear and bending moment as a function of $x$ for a beam with two vertical loads.

This shows how to take an expression given by the student and plot the implicit curve of points where it equals zero.

Student calculates $\bar{y}$ for a triangle.  Must use similar triangles get element $dA$.

Find the area, first moment of area, and coordinates of a general spandrel.  The area may be above or below the function.

When saving the data necessary to resume an attempt, Numbas only saves the values of variables which use the random number generator.

If you naively generate a large random sample in one variable, it'll be marked as a source of randomness so Numbas will save every value in the sample. Loading this value when you resume the attempt can be very slow.

Instead, you can generate a seed value in one variable and then use it with the seedrandom function in the variable that stores your random list. Only the value of the seed needs to be saved.

The diagram contains a line and a hidden glider on that line.

The JavaScript preamble adds a callback which shows the glider when the question advice is displayed.

Shows how to use the lpad function to format a time in HH:MM format so that leading zeros are used for numbers less than 10.

The CSS preamble adds a vertical line down the input for part b, to separate the two parts of the matrix.

Locate the centroid of a rectangle, triangle, and semi-circle on a coordinate grid.

A custom marking algorithm on the spreadsheet part changes it to interpret quantities in cells, so they can be compared to the expected answer.

In real use, you'd probably want more sophisticated logic, to give better feedback or to allow partial marks for different units, like the "quantity with units" part type does.