removing slide numbers in r markdown

Question

How can I remove slide numbers from Rmarkdown beamer presentation using a 'madrid' theme. Additionally how can I specify or increase the font size

---
title: "Title"
author: "Keniajin"
output:
  beamer_presentation:
    theme: "Madrid"
    colortheme: "default" 
    fonttheme: "professionalfonts"
header-includes:
- \usepackage{booktabs}
- \usepackage{longtable}
- \usepackage{array}
- \usepackage{multirow}
- \usepackage{wrapfig}
- \usepackage{float}
- \usepackage{colortbl}
- \usepackage{pdflscape}
- \usepackage{tabu}
- \usepackage{xcolor}
- \usepackage{threeparttable}
- \newcommand{\columnsbegin}{\begin{columns}}
- \newcommand{\columnsend}{\end{columns}}
- \newenvironment{knitrout}{\setlength{\topsep}{0mm}}{}
fontsize: 30pt
---

## Background

This is background

## Histrory

Hii story ya

## Methods

### Method A - about this

I tried using \\setbeamertemplate{page number in head/foot}{} and it was not successful.

Answer 1

The Madrid beamer theme uses the infolines outer them which, in turn, sets

\setbeamertemplate{page number in head/foot}[totalframenumber]

Based on the beamer user guide :

beamer -Template/-Color/-Font page number in head/foot

These beamer -color and -font are used to typeset the page number or frame number in the footline.

The beamer -template provides a convenient way to format the page or frame number in the footline. It is used by the infolines outer theme and the page number and frame number footline themes. It can also be used with the miniframes and split outer themes, but for them it is set to empty as default.

The following template options are predefined:

• [default] The default option is empty.

• [framenumber] This option inserts the current frame number.

• [totalframenumber] In addition to the current frame number, this option also shows the total number of frames.

• [appendixframenumber] This options replicates the behaviour of the appendixnumberbeamer package. In the main part before the \\appendix command the current frame number and the total number of frames in the main part is displayed. In the appendix only the frame number within the appendix and the total number of frames in the appendix are shown.

• [pagenumber] Shows the current page number.

• [totalpagenumber] In addition to the current page number also the total page number is displayed.

You need

\setbeamertemplate{page number in head/foot}[default]

---

It is not advised to change the font size of your document, but rather change the paper size. This indirectly adjusts the font size. If you wish to "increase [decrease] the font size", choose a smaller [larger] paper size. The default paper size for a beamer presentation uses a 4:3 aspect ratio (the document class option aspectratio = 43 ) with a paper size of 12.8cm x 9.6cm, set internally using geometry . If you want to have your font size 20% larger (say), choose a paper size that matches the aspect ratio at 80% of the default size (12.8cm x 80% = 10.24cm; 9.6cm x 80% = 7.68cm):

\geometry{papersize = {10.24cm, 7.68cm}}