realizată de yasmin ahmed 12 luni în urmă
292
Math 280
realizată de yasmin ahmed 12 luni în urmă
292
Mai multe ca aceasta
Problem Solving
Jim,Ken, Len and Max have a bag of miniature candy bars from trick-or treating together. Jim took 1/4 of the bars, and ken and len took 1/3 of all the bars. Max got the remaining 4 bars. How many bars were in the bag originally?
Max 4 bars
Jim 1/4= 3/12
Ken 1/3= 4/12
len 1/3
All: 12x4= 48
Jim: 3x4=12
Ken: 4x4=16
Len 4x4=16
*go look at your notes for the examples
3/4 class is girls, 2/3 have dark hair what fraction of the class is g+dh?
2/3x3/4=6/12=1/2
Meaning
Part of a whole
Quotient -----> 3/4 = 3/4
Ration -----> 20 students
15 girls
5 boys
Ratio Part of a whole
Ratio+fraction
Models
1 whole "pie"
Hexagon
1/2
Trapezoid
2/4
Rhombus
1/3
Triangle
1/6
Mixed #: a number that has a whole and fractional part
If you add fractions with the same shaped blocks!
Turn into an improper fraction
3 1/2
3x2=6+1=7---> 7/2
Adding
GCF: 4,8,12,16,20,24
LCM: 6,12,18,24
1/4+1/6= 24
2/12+3/12= 5/12
Prime factorization
24
2 12
3 4
2 2
2= 2x2x2x3
Greatest Common Factor( GCF)
Least Common Multiple (LCM)
List Method
Factors
24: 1,2,3,4,6,8,12,24
36: 1,2,3,4,6,9,12,18,36
GCF is (24,36)= 12
Multiple
24,48,72
36,72
LCM(24,36)=72
GCF (24,36)= 2x2x3=12
LCM (24,36)= gcfx2x3
=12x2x3=72
Divisibility rule
A number is divisible by a number if there is another number that meets this requirement
BxC=A
Ex.
10 divisible by 5 because 5x2=10
5x2=10
Factor
5 is a factor of 10
2 is a factor of 10
10 is divisible by 5
10 is divisible by 2
Ending Sum of Digits
by 2: 0,2,4,6,8 by 3: 120
by 5: 0,5 by: 7,038
by 6: If it is divisible by both 2 and 3
Last 2 Digits
72,744 <---- yes because 44 goes into 4
824<-------- 24 goes into 4
Last 3 Digits
by 8
7,239 <----- take the last 3 digits
by 7:
826 <----- Double the 6
By 11? "chop off
Adding
American Standars
Partial Sums
Partial Sum w/place value
Left- To- Right
Expanded notation
Subtraction
American Standard
European/Mexcian
Reverse Indian
Left to Right
Expanded notation
Interger Subtraction
Campare >,<,=
are used to make comparisons in mathematics and programming.
a) 34(base5) __<__34(base6)=
(3x5)+4x5)
15+4=19
b) 4(base7)_=__4(base8)=
(4x7)=28 (4x8)=32
c) 43(base5)___25(base6)=
(4x5)+(3x5) (2x6) x (5x6)
20+3=23 12+5= 17
Division
15 cookies
3 on each plate
15 cookies
5 plates
15/5
15 cookies
xxx= 15-3 =12
xxx= 12-3=9
xxx= 9-3=6
xxx=6-3=3
xxx=3-3=0
Atternative algnithm
16/197
160-----------> 10 boxes
37
-16 ------------> 1 box
--------
21
-16 --------> 1box
Base -10
system
or
Decimal
Base -5: 0,1,2,3,4
One= 5
Five=5
25= 5(square)
125= 5 times 3
221(base 5)= (2x25)+(2x5)+(1x1)
= (2x5(2))+(2x5(1))+(1x5(0))
= 50+10+1
Use expanded notation
In the expanded notation of a number, each digit is separated and written with its corresponding place value
Example: 452 written in expanded notation as:
4x100+5x10+2x1
4= 400
5= 5 tens
2= 2 units
1) 111 base 2 = (1x2(2))+(1x2(1))+(1x2(0))
= (1x4)+ (1x2) + (1x1)
= 4+2+1=7
4 ways to solve a problem
Device a plan
Carry out the plan
