Decimals

Question 0

Decimals as Fractions

Answer 0

Start with halves, fifths and tents as families.
Explore tents visually and link to number line. Repeat with hundreds. Colour rows of ten, 10x10 grids to symbolically link decimals and fractions.
Name decimals ‘three and four tenths’ not ‘three point four’.

Question 1

Underpinning notions of decimals?

Answer 1

Decimals are numbers can be found of the number line.

Fractions of denominators that are powers of tens.

Question 2

Decimals & Place Value

Answer 2

The more numbers to the right of decimal does not mean the number is bigger.
Learners need to understand what happens to numbers continuously divided and multiplied by 10 (use calculator).
The more numbers after the decimal to more exact, but less significant- gives meaning to rounding.

Question 3

Ratio & Proportion

Answer 3

2:3 boys to girls, whole class proportions =12:18
Ratio & fractions- 2:3 means 5 parts of the whole = 2/5 boys and 3/5 girls.
Avoid ':' and say 'for every ... there is ...'
Visual & Mental- more comfortable they generate proportions from simple ratio using multiplication.

Question 4

Rate

Answer 4

Associated with ratio.
Describes relationship between 2 different measures.
$1AU : $0.68US

(1/0.68 = 1.47)