All From 9 and the Last From 10 - PART 2

                                   ADDING ZEROS

 In all of the previous  sums you may have noticed that the number of zeros in the first number is the same as the number of figures in the number being subtracted. For example 1000–481 has three zeros and 481 has three figures.
Suppose you had 1000 – 43. This has three zeros, but 43 is only a 2-figure number.
You can solve this by writing 1000 – 043 = 957. You put the extra zero in front of 43, and then apply the formula to 043. 10000 – 58. Here we need to add two zeros: 10000 – 0058 = 9942. 

In the following exercise you will need to insert zeros, but you can do that mentally.

  Practice A  Subtract the following: 

a )1000 – 86      b) 1000 – 93     c) 1000 – 35     d) 10000 – 678     e) 10000 – 353      f )10000 – 177     g) 10000 – 62    h) 10000 – 85 i )1000 – 8       j) 10000 – 3

                                           

                                          ONE LESS

 Now let’s look at 600 – 77. You have 600 instead of 100. In fact the 77 will come off one of those six hundreds, so that 500 will be left. So 600 – 77 = 523 The 6 is reduced by one to 5, and the All from 9 . . . formula is applied to 77 to give 23. 5000 – 123 = 4877. The 5 is reduced by one to 4, and the formula converts 123 to 877.  

   Practice B  Try these: 

a 600 – 88       b 400 – 83     c 900 – 73     d 6000 – 762    e 2000 – 979      f 50000 – 4334                    g 70000 – 8012

                                      ONE MORE

Find 8000 – 4222. Considering the thousands, the 8 will be reduced by 5 (one more than 4) because you are taking over 4 thousand away. All from 9. . . is then applied to the 222 to give 778. So 8000 – 4222 = 3778.

When you have a sum like 8000 – 4222 where both numbers have the same number of figures:  

Reduce the first figure of the first number by one more than the first figure of the second number to get the first figure of the answer. And apply the formula to the remaining figures. 

Practice C Subtract the following:

 a 8000 – 3504    b 5000 – 1234    c 300 – 132    d 2000 – 1444    e 700 – 232    f 60,000 – 23,331