Visual Models and
the distributive
property:
Standard Algorithm
MONDAY, SEPTEMBER 14, 2014
Mental Math
 9x10
9x10= 90
 9x9=90-___
9x9=90-9
 9x9=______
9x9=81
Multiply by multiples of 100
31x100=
3100
3100x2=
6200
31x200
6200
Word Problem of the day!
 Diamond
is setting up a play space for her
new puppy. She will be building a fence
around part of her yard that measures 29
feet by 12 feet. How many square feet of
play space will her new puppy have?
(If you have time, is there more than one
way to solve this question)
Answer:

29x12
29 is close to 30 so…
29=30-1
(12x30)-(12x1)= 360-12
348
21x5
Can
you solve this problem
mentally?
Can
we represent this problem
using an area model?
23x31
23
23+690= 713
1
1x23= 23
30x23= 690
30
343x21
343
1
1x343= 343
20x343= 6860
20
343
X 21
343
6860
7203
231x32
7392
Problem Set

You may work with one other student on your problem set.
I will be calling groups to my back table.
Please keep the noise down or we will work independently.
*** If you are confident with this topic please move your number over
to willing to help***
Exit Ticket
 Complete
the area model then solve
using the standard algorithm
21x23=________
143x12=_______