7D Pace Work 05.10.20

Тема: Ділення двохзначних чисел.

Presentation of new material

     T.: Today we are going to review division of multi digit numbers and solve some problems.

In English-speaking countries, long division does not use the slash (/) or obelus (÷) signs, instead displaying the dividend, divisor, and (once it is found) quotient in a tableau.

The process is begun by dividing the left-most digit of the dividend by the divisor. The quotient (rounded down to an integer) becomes the first digit of the result, and the remainder is calculated (this step is notated as a subtraction). This remainder carries forward when the process is repeated on the following digit of the dividend (notated as 'bringing down' the next digit to the remainder). When all digits have been processed and no remainder is left, the process is complete.

We already know how to do divisions whose divisors were two digit numbers. In this lesson we will learn to do divisions with a three digit divisor.

     T.: Let’s start with an example.

1235 ÷ 123 = ?

First, we will write this in the long division method.

Now let’s start dividing. Are there any 123’s in 1? Nope. What about in 12? Nope. OK, let’s consider the next digit. Are there any 123’s in 123? Yes, there is exactly one. So let’s write 1 on top of 3.

Next is the multiplication step, 1 times 123 is 123. We know that multiplying 1 by any other number gives that number as the answer. Let’s write 123 below like this:

 Now we have the subtraction step

So 123 minus 123 is zero. Let’s write zero. And zero can’t fit any 123’s in it so we have not made any mistakes.

Now we can bring down the 5 next to the zero. 

Let’s start dividing 5 by 123. We can’t fit any 123’s in 5 so we will write zero on top of the bar.

Next we have our multiplication step. Zero times 123 is zero. Let’s write zero below 5 like this,

 Now let’s subtract them:

5 minus 0 is 5. 5 can’t have any 123’s in it. So all is good.

Now we have finished dividing. And now we can say that 1235 divided by 123 is equal to 10 with a remainder of 5

1235 ÷ 123 = 10, remainder 5

No matter how big the numbers are all you have to do is carefully follow five steps:

Divide Multiply Subtract Check Bring Down

     T.: In order to improve your knowledge we should solve some problems.

     T.: Let’s do other examples.

1) 23421 ÷ 352 = ?   

   

2) 58391 ÷ 976 = ?

      T.: Now, let’s divide 3 digit numbers by a 2 digit numbers with no remainders. (card #1).

Then, let’s divide 5 digit numbers by a 2 digit numbers with no remainders. (card #2)

Card #1

Card #2