text: First of all, know the serieses allotted to different service providers such as BSNL, Air Tel etc. They have specific numbers. with this half of the number can be remembered easily. and for balance say the number rythemically or whether the number can be fitted in even or odd series. and finally remember the total of the number. For example 9826883422 can be remembered like 9+8+2+6+8+8+3+4+2+2=52 5+2=7. Like this.