This activity is also part of one or more other Books. Modifications will be visible in all these Books. Do you want to modify the original activity or create your own copy for this Book instead?
This activity was created by '{$1}'. Do you want to modify the original activity or create your own copy instead?
This activity was created by '{$1}' and you lack the permission to edit it. Do you want to create your own copy instead and add it to the book?
Waar plaats je de getallen van 1 tot 20 in een twintigveld? Hoe kan je optellen en aftrekken zonder en met brug met het twintigveld als hulp?
Kijk hoe het moet en oefen.