Arithmetic Grade Four

Lesson One hundred and twenty-seven: Dividing by Multiples of TEN


Dividing three digit numbers by multiples of ten may be a bit more challenging for you. Let's look at a few examples:


         456 / 50 = 9 r6

         Let's check that:

             50 x 9 + 6 = 456

         So, we can get 9 50s out of 456 with 6 left over.

Here's another example:

       377 / 40 = 9 r 17

       To check that we just multiply and add like this:

          40 x 9 + 17 = 377

       We could count by 40s if we really wanted to until the last
       multiple of 40 that's less than 377 and then subtract:

       40, 80, 120, 160, 200, 240, 280, 320, 360. (that's 9 multiples)
 
       377 - 360 = 17 (that's our remainder)

One more example:

      892 / 80 = 11 r12

      Check with multiplication and addition:

          80 x 11 + 12 = 892

      Counting multiples and subtracting:

      80, 160, 240, 320, 400, 480, 560, 640, 720, 800, 880. (that's 11)

      892 - 880 = 12


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