dose 18 go into 45

Question

dose 1.8 go in to 45 long division 

Answer 1

Strategy: we have to divide 45 by 1.8, so set up the long division as follows:

     _____

1.8|45

 

With decimal fractions, we want to get rid of the fraction, that is, instead of having 1.8, we'd rather have 18.  To do this, move  the decimal point one space to the right on the 1.8.  This amounts to multiplying by 10, 1.8x10=18.  To compensate, we need to also multiply the 45 by 10. 45x10=450.  Our long division now becomes:

    _____

18|450

 

(Summary: we changed the 1.8 to 18 by multiplying by 10 and the 45 to 460 by multiplying by 10)

 

We can now complete the long division in the usual way.

 

Step 1: Divisor is 18, dividend is 450.  Start with the leftmost digit in the dividend, "4". Can 18 divide into 4?  No.  Move to next digit.

 

Step 2:

    ____

18|450

 

We're now on the "5".  Can 18 go into 45? Yes.  How many times?  Let see: 1x18=18, 2x18=36, 3x18=54.  3 is too big. 2 is what we need.  Write a "2" above the "5", and muliply 18 by 2, placing the result (36) below the "45":

    _2__

18|450

     36

 

Now, subtract the 36 from the 45, and write the result below,

     _2__
18|450
     36

       9

Now, move to the last digit, "0" and on to step 3:

 

Step 3:

 

The "0" gets moved down, next to the 9:

 

     _2__
18|450
     36↓
       90

 

Now, repeat the process, asking how many times can 18 go into 90.  I'll leave this step to you, but if the answer is a whole number of times, with no remainder, then yes, 1.8 does indeed go into 45 with no remainder.