How much is 5 Â² ? How about 12 Â² ? Well, if you have already finished the gymnasium then maybe you are already used to find the square for these numbers. But how about 104 Â² ? I found…

## Fast multiplication n-digits (on certain situations)

I've found a solution for fast multiplication n digits with respect to the following conditions: have the same number of digits the first digit of both numbers are equal the sum of last digit of both numbers is 10 Example…

## Fast multiplication by 11

One of my favourite techniques is that which allows us to fast multiplication by 11. To get your attention I will say that I can multiply in my head the following numbers: 748346274 x 11 = 8231809014 The technique is…

## Fast multiplication 3 digits

Are you scared when comes to multiply a product like 123 x 321 in your head? Well, that's not so hard as it seems to be! Fast multiplication 3 digit For this we can use a technique which reduce the…

## Fast multiplication 2 digits

How do you calculate how much is 93 x 97 in your head? Sounds that impossible? There are many quick algorithms depending on the nature of the numbers you want to multiply. In some situations fits better one algorithm, in…

## Alternative to Xfce calendar panel

I don't want to install and use the Xfce calendar plugin, because 99% of time I don't need it (so why should I keep the laptop memory busy all the time with something that I rarely use?) As alternative I…

## xorg-server no mouse or keyboard

I just started my Gentoo and then my X session. I have noticed that neither mouse or keyboard is working (even if it works ok before starting X). The answer lies in /var/log/Xorg.1.log file. Just search for these lines which…

## Handle the network connection on suspend / resume

Whenever I have suspend/resumed my Gentoo system I found my wifi network status as started but actually not working. I guess that standby/hibernate/suspend is handled by sys-power/pm-utils, which is very well described here, I can make use of it to…

## Geometrie clasa a VIII-a

Tabla de materii Relatii intre puncte, drepte si plane puncte, drepte, plane: conventii de desen si notatie determinarea dreptei; determinarea planului piramida: descriere si reprezentare; tetraedrul prisma: descriere si reprezentare; paralelipipedul dreptunghic; cubul pozitii relative a doua drepte in spatiu;…

## Algebra clasa a VIII-a

Tabla de materii Numere reale Reprezentarea numerelor reale. Modulul unui numar real. Intervale de numere reale Operatii cu numere reale; Calcule cu numere reale reprezentate prin litere; formule de calcul prescurtat Descompuneri in factori (factor comun, grupare de termeni, formule…