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The principal did find out and called
Ranjit to his room. “Young fellow, so youdon’t want to stand in your place, is it?
If you want to stand in the Class 6 row,
you have to increase your value bystudying well and
learning well todeserve the value
of being in theClass 6 row. Understand?
Now, run to class!”
Ranjit scratched his head,
and walked back to hisclass. What was his value,
he wondered.
He had learnt place value in
arithmetic recently and thisis what he understood about value. The digit
2 means just 2.
When you write 20, the 2 indicates there are 2 tens.
Similarly when you write
2032, the 2 on your rightdenotes just 2 but the 2 on
your left means there are 2thousands.
So, depending upon the
‘place’ where a digit sits, itgets different values.
Let’s take the number 167,234. Each digit here has a different
place value. 1 is in the lakh’s place. In the number 167,234, theplace value of 1 is one lakh. 6 is in the ten-thousand’s place. The
place value of 6 in 167,234 is 60,000. A number is the sum of theplace values of its digits.
.
Ranjit has understood place value quite well now.
Ranjit’s uncle has a car that has the registration number 1945. What is the place value of 9 in it?
900. Hundreds place. 1945 has nine hundreds in addition to 1 thousand, 4 tens and 5 units.
Add 496, 3,051 and 27. Find the digit in the hundred’s place of the sum that you get.
The sum or total of the three numbers is 3,574.
Zzero, do you know
how to multiply with yourfingers?
Of course. I pick up a pencil and
paper with my fingers, write thenumbers and then write the
answers.
No, silly,
I meant with only your fingers.See, here’s how you multiply by 9 with
your ten fingers.
Try this:
Stretch out your fingers.
To calculate
, bend finger
number 1. Count the numberof fingers on either side of the
bent finger. 0 and 9. 9 is youranswer.
. Bend finger 2.
One finger on theleft, 8 on the right of
bent finger. Answeris 18
. Bend finger 3.
Answer=27
Bend finger 4.
Answer=36
Bend finger 5.
Answer=45
Multiplication is a quick way
of adding.
Suppose you pluck 25
mangoes from one treein an orchard, and your
grandmother has askedyou to get 250 mangoes to
make spicy mango pickles,you do not have to keep count
after plucking every mango.
Just pluck 25 mangoes from each tree. Leave
them in separate baskets at the foot of the tree.
One basket contains 25 mangoes.
2 Baskets will contain
mangoes.
You can just multiply 25 by 2 instead.
.
3 baskets x 25 mangoes in each =
.
10 baskets x 25 mangoes in each =
.
When the numbers to be multiplied are
small, it is easy to add repeatedly. Butwhen numbers are big, it is easier to
multiply.
Try this:
Let’s try 24 multiplied by 6. Let’s say you have 20 red marbles and 4 green marbles. Suppose you and five of your friends (that’s 6 of you)want to have the same number and kind of marbles each. When you want 6 times the number of marbles, you will have 6 times thenumber of red marbles in addition to 6 times the number of green marbles, right?
144 marbles. Easy!
Now try this. Multiply 34768 by 987 by the same method. You would have to write . Then multiply each of these by 7, 80 and 900. And add up all the answers to get your finalanswer. Doing this horizontally, then writing it down vertically and then adding the numbers is a very tiring process. To make this work simple,we follow a pattern of writing while multiplying big numbers. .
| 3 | 4 | 7 | 6 | 8 | x | 9 | 8 | 7 | ||
|---|---|---|---|---|---|---|---|---|---|---|
| A. | 2 | 4 | 3 | 3 | 7 | 6 | ||||
| B. | 2 | 7 | 8 | 1 | 4 | 4 | x | |||
| C. | 3 | 1 | 2 | 9 | 1 | 2 | x | x | ||
| D. | 3 | 4 | 3 | 1 | 6 | 0 | 1 | 6 |
It becomes easy to add the numbers vertically, starting from the right, if you write the digits neatly one below the other!
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