Multiplication quiz

This tutorial provides instructions how to create a Scratch Multiplication Quiz.

The quiz will consist of 10 questions where a user will be asked to choose one of 4 answers.

See below definitions of the terms we will use (from https://www.basic-math-explained.com/product-multiple-factor.html#.Wv3CM4gvzFg)

In this case 20 is the product of 4 and 5.

Step 1

Start with opening Scratch editor and choosing 5 characters sprites. It could be Robot1, Giga, Nano, Tera and Pico or any other.

Place first sprite at the top and the rest in line at the bottom (like on the picture in the Overview).

Step 2

Let’s create a variable that will store factors.

Then initiate the variable with a random value between 2 and 12. This should happen every time the “space” key is pressed and in the context of the top sprite (Robot1).

Test your code.

Step 3

Now let’s create 4 valid multiples.

To store multiples we will need a list. You can think about a list as an ordered set of variables.

Go to Data and create a list called “Products”. Make sure it’s accessible for all sprites.

You should see an empty list in the main window.

Now let’s create 4 multiples using “insert”, “random” and “*” blocks.

You will also need a “repeat” loop which executes 4 times.

Test the code. You should get four numbers that are multiples of value stored under the “factor” variable”.

Step 4

Did you notice that every time you press “space” the old values stay in the list, just being pushed out further down?

We don’t need them so let’s clean up the list…

Add “Delete (all)” block from the data blocks.

Test the code.

Step 5

We will now make our characters say the actual products from the list.

Click on first of the bottom sprites and insert following code:

This code will be executed at the same time as the script we created previously so we need as short delay (“wait” block) to allow the list to be populated.

Test your code. The sprite on the bottom left should say the first element of the list.

Now copy this code to the three other sprites (to do it, simply drag and drop to code on the sprite). For each sprite, change the item parameter so that sprite 2 reads second item of the list and so on.

Test your code. You should have all four values displayed like below

We don’t need to see the list anymore so let’s hide it by removing tick from the list block

Step 6

This step is about making one of the products invalid.

To do this we will randomly choose one of the products and then add to it a number bigger than zero but smaller than the base factor.

For example if the factor is 5 and product 25 then the code would randomly choose from following values: 1;2;3;4. Let’s say the random block chooses 3 so the new invalid product value would be 28 (25 + 3).

To code it let’s firstly create a variable WrongProductId.

Now, the tricky two lines of code and one more with user instructions

Test your code. One of the answers should always be wrong.

Step 7

Getting answers and tracking score.

Start with adding a new variable - Score.

Score needs to be zeroed everything we start the quiz so will need a new script that is triggered after green flag is pressed. You can add some instruction for the user at the end of this section.