3.4 Algorithms for Multiplication and Division Remember to Silence Your Cell Phone and Put It In Your Bag!

Modeling Multiplication Base-Ten Blocks Concrete model Draw pictures 1. Multiplying by a 1 digit number Repeated addition model Rectangular array model Area model 2. Multiplying by a 2 digit number Rectangular array model Area model Note – Use the commutative property whenever it makes the problem easier!

Multiplication Algorithms Expanded Algorithm Illustrates what is happening with the base-ten blocks Bridges the modeling using base-ten blocks with the standard algorithm Standard Algorithm

Modeling Division Base-Ten Blocks Concrete model Draw pictures 1. Finding how many subsets – repeated subtraction 2. Finding how many in each subset – sharing

Division Algorithms Repeated Subtraction Algorithm Standard Algorithm

Order of Operations 1. Compute within grouping symbols first, working from the inside out. 2. Compute powers. 3. Multiply and divide in order from left to right. 4. Add and subtract in order from left to right.