Repeated Subtraction for Division
There are many different strategies that can be used to solve a division problem. One strategy
that students will learn is repeated subtraction.
Using a division equation students will solve the equation by subtracting from a whole number
until there is nothing left. The answer to the division equation is determined by how many times
you subtracted from the whole number to get zero.
Example:
15 ÷ 5 = 9
15 – 5 = 10
10 – 5 = 5
5–5=0
Since 5 was subtracted from the whole number three times to get zero, the quotient of the
problem is 3.
Using a Number Line to Multiply
The number line can be used to help students with skip counting and visualizing a
multiplication problem. A multiplication sentence is created using “jumps” along a number line.
1st jump
2nd jump
3rd jump
4th jump
For example, 4x5 can be represented as 4 “jumps” of 5 along a number line. The point where you
end after the “jumps” is the product, 20 in this case.
Count Equal Groups
Equal groups have the same number in each group.
There are 3 flowers in each of 4 vases. How many flowers are there in all?
Step 1 Think: There are 4 vases, so draw 4 circles to show 4 equal groups.
Step 2 Think: There are 3 flowers in each vase, so draw 3 dots in each group.
Step 3 Skip count by 3s to find how many in all: 3, 6, 9, 12
There are 4 equal groups with 3 flowers in each group.
So, there are 12 flowers in all.
1. There are 5 tables in the library. Four students are sitting at each table.
How many students are sitting in the library?
A. 9
B. 16
C. 20
D. 24
2. Stella decorated using 4 groups of balloons. She drew this model to show the number of
balloons.
How many balloons did Stella use to decorate?
A. 3
B. 6
C. 9
D. 12
The open number line is a power tool that promotes powerful mathematical
thinking. It helps children to show and explain their invented strategies, builds
flexibility with numbers and scaffolds the mental representation of number and
number operations to support mental arithmetic strategies (Fosnot,2007 ; Beishuizen,
1993 & Gravemeijer, 1991).
Open number lines can be used to solve many types of problems.

Rounding

Addition

Subtraction
http://www.bing.com/videos/search?q=learnzillion+rounding+on+a+number+line&FORM=HDRSC3#vie
w=detail&mid=31135BF55ED87D44405F31135BF55ED87D44405F
Repeated Addition
5 × 2 = 10
Here we have five groups, and each group has two elephants.
how many
groups
5
“Five
how many
in each group
×
2
times two elephants
We can solve
it by adding:
=
2 + 2 + 2 + 2 + 2 = 10
is
ten elephants.”