Addition Methods | Adding by Parts

Adding two or more numbers can be fun and easy when done in parts - by parts I mean unit, ten, hundred,....

For example

Work out the value of 5 + 15 + 34 + 58 + 72

add the tens:                      10 + 30 + 50 + 70 = 160  (you see, 70 + 30 give 100, 10 + 50 give 60 )
add the units:               5 +  5  +   4 +   8 +  2 =   24    (5 + 5 = 10, 8 + 2 = 10: that's 20, plus 4 give 24)

Now add 160 and 24

160 + 24 = 184

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Maths is Fun ^o^

Division Methods | Long Division and Division by Chunking

These two methods can be very useful. I recommend introducing them together - give the students options to work with.
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Method 1 - Long Division

Solve 351divided by 9

 Steps

1. 9 goes into 35, 3 times

2. 9 x 3 - 27

3. 35 - 27 = 8 ......bring the unit, 1, down. That makes 81

4. 9 goes into 81, 9 times.

5. Now, 81 - 81 = 0....no remainder, the answer is 39

 

Note: If there is remainder, your answer will be a mixed number (or a decimal number)

 

Method 2 - Division by Chunking - This is about calculating in parts

Solve 351divided by 9

351
  81        (9 x 9) .....you know that from x9 table
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270        (9 x 30)

ANSWER 39 ......add 30 and 9 to give you the answer (easy aye :))


YOUTUBE Links
Long Division
Division by Chunking