What is 7000000-700, i know the answer still how shud i subtract it i dont know the method

Question

My question is 7000000-700, the answer is 6999300 but what is the method of doing it? 

Answer 1

Addition and subtraction are taught to very young children.  When the sum or the difference results in a non-negative, single digit, the problem is pretty easy; the extra step comes with the "carry" (in addition) or the "borrow" (in subtraction).

 

First be sure to line up the digits from right to left (since WyzAnt Answers Forum uses proportional type, I will put letters above the columns, right to left).

 

Subtraction problem:

    G    F    E    D    C    B   A

 

    7    0    0    0    0    0    0

                          -7    0    0

  ---------------------------------

 

A)  subtract 0 from 0 and get 0.

     G    F    E    D    C    B    A

 

     7    0    0    0    0    0    0

                           -7    0    0

  ---------------------------------

                                        0

 

B) Subtract 0 from 0 and get 0.

     G    F    E    D    C    B    A

     7    0    0    0    0    0    0

                           -7    0    0

  -----------------------------------

                                  0    0

 

C) Cannot subtract 7 from 0, so we "borrow" 1 from column D and subtract 7 from 10 giving 3.

     G    F    E    D    C    B    A

     6    9    9    9    10   0    0

                            -7    0    0

   --------------------------------

     6    9    9    9    3    0    0

 

Note that "borrow 1 from D, which is 0, means that you must also borrow 1 from E, which is 0, and you must borrow 1 from F, which is 0, so you must borrow 1 from G, which is 7.  That makes it:

     6    9    9    9    10    0    0

 

The borrowing may stop when 1 is borrowed from a number (for example, 7) that is larger than 0 (that is, it is 1-9).

Answer 2

Borrow from the thousands place

 

7 000 000  - 700 =

 

(6 999 000 + 1000) - 700 = 

 

6 999 000 + (1000 - 700)=  <---- note that the 700 is negative as it is being subtracted

 

6 999 000 + 300 =

 

6 999 300