Add checkmarks to a to do list using animation in PPT 2013

You can apply the check symbol directly using the bullet button on the home tab. All the numbered items will have the check. But that leaves you with no flexibility, you have no impact on how and when the check will appear. The first item is already checked and every next item will also be when you press enter.

Create your list using the appropriate numbering style or use no numbering.

Draw a text box, add the check symbol using Insert - Symbol - Wingdings2 font.

Position the text box next to the numbered/unnumbered item.

Copy and paste the text box as many times as necessary to add a check next to each item in the list.

Animate the check symbol for the previous item when the next item appears

Select the placeholder and add an entrance effect. All of the paragraphs get a separate animation.

Select all of the text boxes (to select drag with the mouse around the checkboxes) and add an entrance effect.

Your animation pane should look like this:

Select all of the check box animations except the last and in the timings tab select 'With previous' next to start. Select the last item and select 'On click' next to start. 

Now drag each item under the next animation:

Animate the check symbol at the same time as the list item

Drag the check box animations under the same numbered item. The animation starts with previous. 

Using the same animation for the list item and the text box is your best bet. Using different animations for the list item and the text box may result in having to adjust the timing.