Matematica

toc

sin calculadora:
media type="youtube" key="Zf8Srruz44I&hl=en" height="355" width="425"

La tabla del nueve
media type="youtube" key="_13v-vGCMM8&hl=en" height="355" width="425"

Otra forma!
media type="youtube" key="gbvR7ynSSfY&hl=en" height="355" width="425"

= =