Document Sample

```					Place Value / Multiplying and Dividing by 10 &
100

Teaching Points:
Pupils need to visualise the value of numbers and the
relevance of being located in a specific column.
Use the concept of money to introduce decimal
notation.

Activities:
 Give a group of children a number card (between 0 –
9) each and ask them to stand at the front of the
class. Ask them to organise themselves in an order
which will create:
the smallest number;
the largest number;
a number in which the ___ is in the tens column;
a number in which the ___ is in the thousands
column;
and so on.

This type of activity can be repeated for decimal
numbers. One of the children standing at the front
of the class would be given a card with a decimal dot
organise themselves in an order which will create:
The smallest decimal number;
The largest decimal number;
A number in which the ___ is in the tenths column;
A number in which the ___ is in the hundredths
column;
and so on.

N.B. In both of these activities, the whole class
could be asked to do the arranging of the
numbers in order to answer the set question.

 Using number fans (or similar resources), ask
children to show decimal numbers.
Show me: 2.5, 3.7, 14.6
Show me: 8.45, 5.76, 18.74
Show me a number with a: 7, 4, 3, … in the tenths
column.
Show me a number with a: 6, 4, 8, … in the
hundredths column.

Multiplying and dividing by 10, 100

Teaching Points:
Pupils need to visualise the movement of numbers up or
down through the columns.

Teaching Activities:
 Give some children number cards (between 0 – 9) and
a decimal dot card. Ask them to stand in front of
the class, creating any decimal number – it would be
easier for the children to understand the concept of
the numbers moving through the columns, if the
numbers used in the initial stages were small
numbers e.g. 9, 8, 4. However, it is important that
the children see the number as 9.0, 8.0, 4.0 in order
to see the movement of numbers through the
columns and to understand where the 0’s come from.
By multiplying by 10 and 100, the children standing at
the front of the class can physically move through
the columns. This activity can be repeated with the
concept of division.
 Using a pack of number cards (between 1 – 50), the
cards are shuffled and placed face down in a pile.
One child takes a card from the pile, hides it from
the rest of the children and then says out loud,
“The result of multiplying it by 10 (or 100) is
________. What is the number?”

As long as the children are familiar with decimal
notation and have understood the concept of
dividing by 10 / 100 – the numbers moving
through the columns – they should be able to do
this activity with dividing by 10 or 100.

 Before doing this activity, the children need to be
familiar with an abacus and what each of the poles
represents.

 Using an abacus, place one bead on the units
pole. Ask the children what ‘1 x 10’ is and then
show the movement of the one bead from the
units pole to the tens pole. Repeat this
exercise for a variety of single digit whole
numbers (4, 5, 7…).

This activity can also be done to
demonstrate what happens when multiplying
by 100 and can also be done to demonstrate
what happens when dividing by 10 and 100.

 Before doing this activity, the children need to be
familiar in how to use a calculator. The children
need to work in groups of 4 for this activity.

 The first person keys a 2-digit number into the
calculator and then passes the calculator onto
the second person.
 The second person reads out the number and
passes it to the third person.
 The third person multiplies the number by 10
(or 100, depending on the focus) and says this
answer out loud (they mustn’t use the calculator
to do the calculation). After doing this, they
pass it to the fourth person.
 The fourth person checks the answer called out
by child 3, using the calculator to do the sum.
 Repeat this activity several times, taking turns

N.B. This activity can be also be done for
dividing by 10 and 100. Just ensure that the
number keyed in by the first child is large
enough to be divided by 10 and / or 100.

```
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
 views: 6 posted: 9/11/2012 language: Unknown pages: 5
How are you planning on using Docstoc?