Adding beyond twenty
<div id="top-row" class="style-scope ytd-video-secondary-info-renderer">
<div id="upload-info" class="style-scope ytd-video-owner-renderer">
<div id="container" class="style-scope ytd-channel-name">
<div id="text-container" class="style-scope ytd-channel-name"><a class="yt-simple-endpoint style-scope yt-formatted-string" spellcheck="false" href="https://www.youtube.com/channel/UCXl0Zbk8_rvjyLwAR-Xh9pQ">Insights into Mathematics</a></div>
</div>
65K subscribers</div>
<div id="sponsor-button" class="style-scope ytd-video-owner-renderer"> </div>
<div id="analytics-button" class="style-scope ytd-video-owner-renderer"> </div>
<div id="subscribe-button" class="style-scope ytd-video-secondary-info-renderer">SUBSCRIBED
<div id="notification-preference-toggle-button" class="style-scope ytd-subscribe-button-renderer"> </div>
<div id="notification-preference-button" class="style-scope ytd-subscribe-button-renderer"> </div>
</div>
</div>
<div id="content" class="style-scope ytd-expander">
<div id="description" class="style-scope ytd-video-secondary-info-renderer">The standard addition table gives us sums of numbers up to 10+10=20. Now we want to explain how to teach young people how to progress further with successive additions, involving wrapping around 20, and then 30, and then 40 and so on. Our physical representation of addition as combining row rectangles is important here, as it gives us a direct appreciation of wrapping. That use of a 10 table extends to sums going beyond 20. The aim is for students to be able to perform sums like 5+2+7+6+6+9=35 consistently from left to right, using always the basic addition table together with the idea of wrapping. This kind of facility should be mostly in their heads, although some might benefit by saying that sum to themselves as the proceed methodically. And of course calculators play absolutely no role here!</div>
</div>