Counting quiz for children
First off I noticed a problem in how the quiz chooses the numbers:


It can easily happen that two (or more) numbers are the same. Especially when picking number between 1..5. In that case it can be confusing to the user, which of the two equal numbers should he click.


The main problems with the code resides in tight coupling between UI logic and business logic. For example the createPoints() function:

function createPoints(count) {
    let contentInner = document.getElementById('contentInner');

    for(let i = 0; i &lt;= 2; i++) {
        let num_ = Math.random() * count;
        let num = Math.ceil(num_);

        let pointEl = document.createElement('div');
        pointEl.className = 'point';
        pointEl.id = 'point_' + i;
        pointEl.setAttribute('data-num', num);
        pointEl.innerHTML = num;

        contentInner.appendChild(pointEl);
    };
};


This function both:


generates three random numbers and
displays the numbers on page.


Would be better two have two functions that separately perform the tasks, something that could be used like so:

displayNumbers(randomNumbersBelow(10))


Also note the naming: the original name createPoints() seems to be talking about some coordinates, which doesn't sound correct to me.

By separating the two, it should be also easier to improve randomNumbersBelow() function so that it would not return duplicates, without having to modify anything inside displayNumbers().

Additionally:


num_ variable can be easily eliminated by inlining the expression: Math.ceil(Math.random() * count).
Instead of modifying the contentInner element by itself, it could just return the new contents (e.g. as a DocumentFragment). That would eliminate the need for the existence of clearContent() function.