7G

 Song on formation of soil https://youtu.be/2311yO5opVk Video on Soil profile https://youtu.be/bgqea0E2eAY

Mathematics: Easy Trick for multiplying 2-digit numbers You must be knowing the normal trick of multiplication which your teachers taught you. It goes like this:             Ex: 37×77                                                                    4                                           4                         37                      ×77                        259                  +2590                    2849       But this is the easiest trick. In this, you have to firstly follow some steps: 1.                     Multiply the right-hand side numbers. Whatever the answer comes is your one’s digit of the answer. If the product is a two-digit number then write the one’s digit in the one’s place and keep the ten’s digit number as a carryover. Ex:   37 × 77                    4 37   ×77 9 2.                     Then multiply the numbers which are in cross. Then add their products and the carryover (in s