Maths Revision

As homework this week 5th Class will be revising the following mathematical topics. The children will receive guidelines and advise but no specific instructions as to what to revise and when. It is hoped that the children will take a degree of independence in their learning and decide for themselves which topics they feel they need to spend more or less time on. 

The topics to be revised are as follows;

(1) Long Multiplication.

(2) Angles.

(3) Basic Fraction Principals.

(4) Finding the fraction of a whole number.

(5) Converting fractions into decimals. 

(6) Long Division.

I will upload examples, instructions, methods and images to help with the revision of each topic. In addition the children may or may not decide to use examples from their textbook. 

I advise taking one evening's worth of time for topics 5 and 6. 

Whereas the topics 1,2,3, and 4 could be combined into two evenings worth of time. 

(1) Long Multiplication

(2) Angles 

(a) Acute angle = less than 90 degrees.

(b) Right angle = 90 degrees.

(c) Reflex angle = greater than 180 degrees but less than 360 degrees.

(d) Obtuse angle = greater than 90 degrees.

(e) Straight angle = 180 degrees. 

(3) Fractions (Basic Principals, Finding Fractions of a Number, Converting simple Fractions into Decimals)

What do fractions mean?

Look at the bottom of the fraction first – this tells you how many pieces the shape (or number) has been cut into.  Then look at the top of the fraction – this tells you how many pieces you are using.

(numerator (top))/(denominator (bottom)) 

Examples:

1/4  means “split the shape (or number) into 4

and use 1 piece”

3/5  means “split the shape (or number) into 5

and use 3 pieces”

Remember:

If the top and bottom numbers of a fraction are the same then you have a whole one.  

For example 3/3 means split the shape (or number) into 3 pieces and use 3 of them (in other words the whole thing).

2 halves = 1

3 thirds = 1

4 quarters =1

5 fifths =1

6 sixths = 1   

OR;

2/2=1  3/3=1  4/4=1 5/5=1 6/6=1

Finding Fractions of Numbers: 

Remember our definition of a fraction: the bottom tells us how many pieces to split (divide) the shape (or number) into and the top tells us how many pieces we are using.  So it follows, that we will divide by the bottom number and then multiply by the top number:

To find: 1/2 of a number ÷ by 2 

1/3 of a number ÷ by 3 

1/4 of a number ÷ by 4 etc.

Always divide by the bottom number:

1/3  of 12 = 12 ÷ 3 = 4. (to find a third divide by 3 - the bottom number.)

1/5  of 35 = 35 ÷ 5 = 7. (to find a fifth divide by 5 - the bottom number.)

Then multiply by the top number:

2/3  of 12 12 ÷ 3 = 4 4 x 2 = 8 

(to find 1 third ÷3) (x2 to find 2 thirds)

4/7  of 42 42 ÷ 7 = 6 6 x 4 = 24 

(to find 1 seventh ÷7) (x4 to find 4 sevenths)

Examples:

Work out 2/3 of 42

42 ÷ 3 = 14 then 14 x 2 = 28

Work out 5/9 of 63

63 ÷ 9 = 7 then 7 x 5 = 35