Computation review

Computation Review

by Uel Roberts - Johnson

Poll

Dream vacation

Learning Objectives

By the end of this session, students should be able to:

1. ​Accurately evaluate 3 fractions involving mixed operations.

2. ​Express 3 numbers in their equivalent percentage, fraction and decimal forms.

3. ​Solve 2 worded problems involving percentages.

4. ​Solve 2 worded problems involving ratios and proportion.

Multiple Choice

Say whether proper or improper . . .

$$\frac{\text{5}}{\text{2}}$$  

• Proper

• Improper

Multiple Choice

Say whether proper or improper . . .

$$\frac{\text{6}}{\text{11}}$$  

• Proper

• I

Multiple Choice

State the name for the following:

$$10\frac{\text{1}}{\text{4}}$$  

• Proper Fraction

• Improper Fraction

• Mixed Number

Multiple Select

Which of the following fractions are equivalent?

• 2/3 = 10/15

• 7/9 = 14/16

• 3/7 = 21/21

• 6/11 = 24/44

​Write your own example . . .

The LCM

Means Lowest Common Multiple

​Is the smallest number that all of the numbers in a group can go into without leaving a remainder.

Cannot be smaller than the largest number in the group of numbers.

​

Ex. 5, 10, 15

The LCM cannot be smaller than 15. The LCM is 30.

​

Ex. 4, 12, 20

The LCM cannot be smaller than 20. The LCM is 60.

Multiple Choice

True or False: The LCM is the smallest number that all the numbers in a group can go into without leaving a remainder.

• True

• False

Multiple Choice

The LCM cannot be __________ the largest number in the group.

• larger than

• smaller than

• equivalent to

Multiple Choice

Determine the LCM of 6, 4 and 12

• 12

• 6

• 4

• 2

​Write the LCM of 10, 15, 20

Multiple Choice

To convert from a mixed number to an improper fraction, you ____________________.

• Add the numerator to the whole number and then divide by the denominator.

• Multiply the whole number by the numerator and place the answer over the denominator.

• Multiply the denominator by the whole number, add this number to the numerator and place it over the denominator.

Multiple Select

Tick the correct equations:

• 5 1/2 = 6/2

• 3 4/7 = 25/7

• 2 1/4 = 8/4

• 7 2/3 = 23/3

Multiple Choice

To convert from an improper fraction to a mixed number you ___________.

• Divide the numerator by the denominator, the answer becomes the whole number and put the remainder over the denominator.

• Make the numerator the whole number, subtract the denominator from the numerator and write the answer over the denominator.

Multiple Select

A Fraction ___________________________________.

• Is part of a whole

• Is a ratio of two numbers

• Should be simplified in it's lowest terms

• Has a numerator and a denominator

Multiple Choice

How do you add / subtract fractions?

• Add the numerators and then the denominators

• Make the denominators the same (using the LCM) and then add the numerators

• Make equivalent fractions and then add / subtract

Multiple Choice

How do you multiply fractions?

• Find the LCM and then multiply the numerators and denominators

• Simplify where possible and then multiply the numerators and denominators

• Flip the second fraction and then multiply the numerators and denominators

​Write your own example . . .

Multiple Choice

How do you divide fractions?

• Find the LCM and then multiply the numerators and denominators

• Change the division sign to multiplication and then flip the fraction before (to the left of) the division sign

• Change the division sign to multiplication and then flip the fraction after (to the right of) the division sign

Multiple Choice

To evaluate fractions involving mixed operations, you should:

• Perform the operations in the order that they appear

• Add / Subtract first and then Multiply / Divide

• Apply BODMAS

Poll

BODMAS means

• Bored

  Of

  Doing

  Maths

  At

  School

• Brackets

  Of

  Division

  Multiplication

  Addition

  Subtraction

• I don't know

​Mixed Operations Involving Fractions

• ​BODMAS

• Text book - page 14, problem 19

• ​Practice pg 15 # 1, 3, 5 - 7, 10 and 12

Question 1

​Question 3

Question 7​

Poll

How was that?

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• Good

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​Percentages

• ​A fraction that is out of 100

• ​Literally means per 100​

  Used to give a common standard​

• ​Very common in commercial life and in engineering​

• ​Also used for sale reductions, interest rates, pay rises, exams and VAT.​

• ​Symbol: %​

Multiple Choice

How do you convert a fraction to a percentage?

• Divide by 100

• Multiply by 100

• Add that number that will give you 100 to the denominator, to both the numerator and denominator

Multiple Choice

$$\frac{\text{3}}{\text{4}}$$  expressed as a percentage is ..........................

• 20%

• 30%

• 40%

• 75%

​Let's see how it works

​Text book Page 36 problems 1 - 7

​

​Practice Page 37, Ex 21 # 15

​

​Problems 15, 18 and 19

​

​Ex. 22 # 9, Ex. 23 # 2 and 5

​Ex. 22 #9

​Ex. 23 # 2

​

​Ex. 23 # 5

​

Poll

How was that?

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• Good

• Not so Good

• Terrible

​Ratios

• ​Compares amounts

• ​Are generally shown as numbers separated by a colon

• ​Are expressed in their simplest form

​Let's see how it works....

Page 44 problems 1, 3 and 4

​

​Practice ex. 24 # 1 and 6

​Ex. 24 # 1

​Total no. of paperclips = 333

No. of defective = 9

​So, no. of non - defective = 333 - 9 = 324

Ratio of ​non - defective to defective = 324:9 = 36:1

​

​Ex. 24 # 6

Poll

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