1. Replace 9+9+9+9 with multiplication formula.
2. Replace O.2+0.2+O.2+O.2 with multiplication formula.
3.( 1) The meaning of oral integer multiplication.
(2) A simple operation to find the sum of several identical addends.
Today, we will learn fractional multiplication together.
Blackboard: Fractional Multiplication (1)
Import Method 2: Review the import.
Courseware demonstration:
1. Tell the meaning of the following formula:
9×5 4× 12 6+6+6=( )×( )
Thinking: What is the meaning of integer multiplication?
The significance of integer multiplication: a simple operation to find the sum of several identical addends.
2. Calculation: 2/9+2/9+2/9+2/9 =
What are the characteristics of each addend in this question? How to calculate it?
Students, let's learn a new operation: fractional multiplication. Let the students think about what fractional multiplication is.
Introduction method 3: review, pave the way to introduce topics.
1, show: 3+3=( )×), the lead says: What is the sum of two 3s?
2. Display: 0.3+0.3=( )×), and lead to say: What is the sum of two 0.3 additions?
3. Summarize the meaning of "integer times integer, decimal times integer". Draw out the topic of "Fraction multiplied by integer" and write it on the blackboard.