The lesson batch size controls the number of lessons you learn in a single batch. By default, this is five, so you would learn all of your daily (10) lessons in two separate batches.
You can configure this at any time by navigating to the application settings page.
You can change the slider labeled Lesson batch size to adjust the setting. Any value between 1 and 20 is allowed.
Once you have set it to the desired value, click Save to save it.