MTE 280 Test 2

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MTE 280 Test 2

Week 11

Problem solving cont.

1)There was 3/4 of a pie in the refrigerator. John ate 2/3 of the left over pie. How much pie did he eat?

He ate 1/2 of the whole pie

2) Three-fourths of the class are girls. Two-thirds of the girls have black hair. What fraction of the class is female and dark haired?

1/4+1/4=2/4=1/2

1/2 of the class are girls and have black hair.

Week 10

Solving examples

A set of marbles can be divided in equal shares among 2, 3, 4, 5, or 6 children with no marbles left over, what is the least number of marbles this set could have?

2:2,4,6,8,10….. 60

3: 3,6,9,12,15,18…..60

4:4,8,12,16……60

5: 5,10,15,20,25…..60

6: 6,12,18,24,30….60

The least number of marbles this set could have is 60

Fraction problem Solving

Problem solving example:

Marc opened a pizza box. Inside there was 3/4 of a pizza. Marc ate 1/2 of what was in the box. How much pizza did Marc eat?

Answer: he ate 3/8

Janice is preparing a recipe that calls for 3/4 of a cup of oil per serving. If Janice needs to prepare 2 and 2/3 servings, how many cups of oil will she need?

1 serving: 3/4

She will need 2 cups

Week 9

Spring Break

Week 8

Different denominators

Different denominators

• find the least common multiple of 1/4+1/6

4,8,12,16,20,24,28,32,

6,12,18,24,30,36

1/4*6 + 1/6*4

6/24+4/24 =10/24=5/12

Fractions

What is a fraction?

• A symbol of the relationship between a part of a whole
• Ratio example: boys:students

Even if you do use the LCM to find a common denominator, it still won’t give you the simplest form for the answer.

Dividing a fraction

Leave it, change it, flip it.

Week 7

Prime factorization

Prime factorization is used to find the LCM

24: 1,2,3,4,6,8,12,24

24=2*2*2*3

24=2^3*3

GCF

36=2*2*3*3

What is the GCF of 24 and 36?

24=2*2*2*3

36=2*2*3*3

GCF=2*2*3=12

List method of GCF

24: 1,2,3,4,6,8,12,24

36: 1,2,3,4,6,9,12,18,36

GCF=12

List Method of LCM

24: 24,48,72

36: 36,72

LCM=72

Divisibility Rules

When we say a is divisible by b, if another number c

cxb=a

Example: 24 is divisible by 2 because there is another number that will be multiplied by 2 to get 24.

10 is divisible by 5

5 divides 10

5 is a divisor of 10

10 is a multiple of 5

5 and 2 are factors of 10

Ending of a number: by 2, 5, 10

• Look at end of number if it is divisible

Find sum of number: by 3, 6, 9

• Add all the numbers
• example: 3+9+6=16 so find what’s divisible by 16

Last two digits: by 4

• Use the last two numbers to see what’s divisible

Last three digits: by 8

• use the last 3 numbers to find what’s divisible

Double the last number: by 7

• Multiply the last digit by 2 and then subtract

Chop off: by 11

• chop off the last 2 numbers and then add it by the rest of the numbers