MTH 085 – BASIC MATHEMATICS
CLASS 8: LECTURE NOTES – SECTION 1.4
1.4: MULTIPLYING WHOLE NUMBERS
Basic Terminology
____________________ is simply repeated addition.
For example, we can rewrite 5 + 5 + 5 + 5 = ___________ = _____.
Remember: ____________________ × _____________________ = ______________________
A number is written in ____________________, when it is written as a product of factors.
For example, 20 = __________, ___________, ___________
When a & b are two whole numbers, their product a · b, is both a ____________________ of a and of b.
For example, the multiples of 5 are: ______________________________________________________
(Hint: Each row of a multiplication table lists the first few multiples of that number.)
X
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
MTH 085 – BASIC MATHEMATICS
CLASS 8: LECTURE NOTES – SECTION 1.4
Types of Properties
1. Commutative (from 1.2): _________________________________________________________
2. Associative (from 1.2): ___________________________________________________________
3. Identity (from 1.2): ______________________________________________________________
4. The multiplication property of zero:
________________________________________________________________
Example (with numbers)
Example(with letters)
-
-
__________________________
_____________________________
5. The distributive property of multiplication over addition:
________________________________________________________________
Example (with numbers)
Example(with letters)
-
-
__________________________
Today’s Examples
1. Multiplying one-digit by two-digit factors
2. Multiplying one-digit by many-digit factors
_____________________________