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Policy Issues
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Work on the concepts is vital. The
children should encounter as much practical work as possible. This will assist
their understanding, and avoid some of the problems caused by an unduly abstract
approach to the teaching of Mathematics
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Emphasise the importance of place value
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Emphasise the place which the
environment plays in the teaching of Mathematics
It is important that there is
consistency with regard to methods.
Subtraction
Second Class Programme
3 types of subtraction
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Deduction: If I take 3 from 10, how many
are left?
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Complementary: 3 and what makes ten?
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Difference: What is the difference
between 3 and 10.
Regrouping (Re-naming) is used
throughout the texts to teach subtraction of whole numbers, time and
subtraction of fractions. Previously, the equal addends method (borrowing
and pay back) was recommended because of the difficulties with large numbers
when doing division, but the reduced level of demand with regard to division
means that it is now opportune to recommend decomposition of number as a method
for doing subtraction. However, if the pupils have already learned the equal
addends method, there is no necessity to change methods. It is recommended that
time and addition and subtraction of fractions be taught by using decomposition.
Regrouping : Examples
Subtraction
| 24 |
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You cannot take 8 from 4. |
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8 |
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Open a bundle of 10. Regroup. Now you
have 1 ten and 14 units |
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| 114 |
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8 |
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- Ensure that lots of examples are done involving 0
Long Division
- Use repeated subtraction to introduce concept
- Teach 13 times tables so that the pupils are
facilitated with doing estimations
- Introductory phase is 2 digits divided by 2 digits
- Encourage pupils to make estimates
- Teach rounding off to the nearest 10
Problem Solving
- Read the problem 3 times
- Tell the main idea in your own words
- Find the question sentence
- Pick out the important facts
- How do the facts (numbers) relate to each other?
- Form the number sentences
- Estimate
- Calculate and form an answer sentence
Fractions
To reduce the level of difficulty involved, children will
need activity of a concrete nature so that when each fractions is recorded in
abstract form, it will be associated with a concrete activity.
Sequence of ideas
- Place an emphasis on equivalent fractions
- The idea of a fraction as a shape divided into equal
parts
- Revise the idea of ½ in the environment : half
–hour, half moon
- Identify shapes divided into halves
- Divide shapes into halves and colour each half in
different colour
- Begin a fraction wall showing 1 unit and ½
- Introduce concept of ¼
- Fraction wall with ½ and ¼
- Renaming fractions : ½ = 2/4
- Addition of fractions
- Subtraction of fractions
- Writing mixed numbers: 2½ using concrete apparatus to
show 2½
- Express mixed numbers in fractions : 2 ¼ = 9 quarters
- Introduce idea of numerator and denominator
- Rename fractions in lowest terms using HCF
- Rename fractions through cancelling
Addition of mixed numbers:
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2 |
1 |
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1 |
1 |
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2 |
3 |
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3 |
+ |
3 |
+ |
2 |
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6 |
6 |
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3 |
5 |
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6 |
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| b) |
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3 |
1 |
+ |
4 |
7 |
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2 |
12 |
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7 |
+ |
6 |
+ |
7 |
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12 |
12 |
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7 |
+ |
13 |
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12 |
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8 |
1 |
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12 |
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Subtraction of mixed numbers
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2 |
5 |
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1 |
7 |
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6 |
12 |
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Subtract whole numbers first: 2 – 1 = 1 |
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1 |
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10 |
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7 |
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12 |
12 |
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1 |
3 |
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12 |
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1 |
1 |
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4 |
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| b) |
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5 |
1 |
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1 |
2 |
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2 |
3 |
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4 |
1 |
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2 |
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2 |
3 |
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4 |
3 |
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4 |
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6 |
6 |
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We cannot subtract 4/6 from 3/6 so we change 1 into sixths
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3 |
6 |
+ |
3 |
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4 |
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6 |
6 |
6 |
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3 |
5 |
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Decimals
The most important concept in working with decimals is
that of place value.
| Tens |
Units |
Tenths |
Hundredths |
| 1 |
4 |
5 |
6 |
- Unit strip divided into ten equal parts
- Write fractions as decimal fractions and vice versa
- Identify decimal fractions shaded in shapes
- Write units and fractions in decimal form
- Sequences involving decimals
- Writing decimals on the abacus
- Use notation board to represent numbers
| H |
T |
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1/10 |
O O
OO |
OOO
OOO |
OO |
OOOO
OOO |
- Relate decimals to money
- Introduce hundredths. Use 100 square
- Recording tenths as hundredths
- Writing hundredths as tenths and hundredths
- When multiplying / dividing by 10, 100, 1000, do not
advise the pupils that the decimal point moves to the left or to the right.
It is the digits that move to the left or right.
Time
- Add hours and minutes separately
| = |
2 hours 40 minutes
3 Hours 30 minutes
5 hours 70 minutes
6 hours 10 minutes |
5 hours 20 minutes
1 hour 40
minutes |
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4 hours 80 minutes
1 hour 40 minutes
3 hours 40 minutes |
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