Maths: Language / method to be used for tables, computation etc.
Note:
It is vital that children are in the habit of writing one digit per square in
their maths copies from Junior Infants onwards. Copies should also be ruled
in order to ensure neatness and proper organisation of work.
Addition
| Tables | 2 + 4 = 6 | Two and four is six | |
| Adding a column of single digit no.s without renaming | Computation 1 | T u 0 3 + 4 7 |
Tens & units columns at the top; Begin with the units· Start at the top… 3 and four is 7 |
| Adding a column of 1 /2 /3 digit no.s with renaming | Computation 2 | T u 2 4 + 8 3 2 |
Tens & units columns at the top; · Begin with the units· Start at the top…. 4 and 8 is 12…· [Regroup the 12 into 2 units and 1 ten] “Put down the 2 and carry the one”· 2 and 1 are 3 etc.. |
Subtraction
| Tables | 4 - 2 = 2 | Four take away two is two | |
| Subtracting single digit numbers without regrouping | Computation 1 | T u 0 6 - 4 2 |
Tens & units columns at the top; Begin with the units Start at the top…. 6 take away four is 2 |
| Subtractingtwo or three digit numbers without regrouping | Computation 2 | T u 2 4 - 1 2 1 2 |
Tens & units columns at the top· Begin with the units· Start at the top…. 4 take away 2 is 2…· Move on to the tens· 2 take away 1 is 1 etc..... |
| Subtracting two or three digit numbers with regrouping | Computation 3 | T u 4 4 - 1 6 2 8 |
Tens & units columns at the top· Begin with the units· Start at the top…. 4 take away 6 - I cannot do! …Regroup · Bring over a ten (leaving 3) and break it up into units · Cross out the four ,leaving three· 14 take away 6 is 8· Move on to the tens· 3 take away 1 is 2 |
| Subtracting three digit numbers with regrouping (and with zero tens) | Computation 4 | H T u 5 0 4 -2 1 6 2 8 8 |
Hundreds, Tens & units columns at the top· Begin with the units· Start at the top…. 4 take away 6 - I cannot do! …Regroup · Bring over a ten - But there are no tens – Go to the Hundreds – Bring over a ten (x tens)=100 making ten tens in the tens column· Start again 4 take away 6 - you cannot do! …Regroup · Bring over a ten - Cross out the ten ,leaving nine & bring over the ten – making 14 · 14 take away 6 is 8 · 9 take away 1 is 8 · 4 take away 2 is 2 |
Multiplication
| Tables | 0 x 2 = 0 1 x 2 = 2 2 x 2 = 4 |
Zero twos is zero· One two is two· Two twos are four etc |
|
| Multiplying a single digit no.by a single digit no· | Computation 1 | T u 0 2 x 4 8 |
Tens & units columns at the top;· Begin with the units· Start at the bottom…. 4 twos are 8 |
| Multiplying a single digit no.by a single digit no | Computation 2 | T u 0 5 x 3 1 5 |
Tens & units columns at the top· Begin with the units· Start at the bottom…. Three fives are 15 · Write the 1(ten) under the tens column |
| Multiplying a 2 (or 3 digit) numberby a single digit no. · | Computation 3 | HT u 0 2 4 x ....6 1 4 4 |
(Hundreds) Tens & units columns at the top· Begin with the units· Start at the bottom…. 6 fours are 24 …Regroup; put down the four (units) and carry the 2 (tens) (into the tens column)· Go on to the tens…6 twos are 12 and two (more) is 14 |
| Multiplying a 2 (or 3 digit) numberby a two digit no. · | Computation 4 | H T u 0 2 4 x(3)6 1 4 4 7 2 0 8 6 4 |
Circle the number of tens(3) before you start.· Multiply by the units first as per Computation 3 above.· When multiplying by ten(s) put down a zero and multiply by the number of tens so…put down the zero and multiply by 3· Add the two parts together for the final answer. |
Division
| Tables | 3÷ 3 = 1 6 ÷ 3 = 2 9 ÷ 3 = 3 |
Three divided by three is one· Six divided by three is two· Nine divided by three is three | |
| Dividing single digit no. by single digit | Short Division |
__2 3[ 6 |
Three into six goes twice |
| Dividing a two or three digit no.by a single digit no with or without remainders | Short Division 2 | __072 R 4 5 [364 |
· Five into three won’t go; Put down the zero and carry the three.· Five into 36 goes seven times remainder 1;Carry the one Five into 14 goes twice rem 4· Write the answer underneath the computation as follows: Ans: 72 R4 |
| Dividing a two (or more) digit no.by a two digit no. with or without remainders · | Long Division | __0049 25[1234 ........100 ...........234 ...........225 9 Ans:49 R9 |
25 into 1 won’t go; Put down the zero and carry the 1 .· 25 into 12 won’t go; Put down the zero and carry the 12. · 25 into 123 goes four times remainder 23; Carry the 23 .· 25 into 234 goes 9 times remainder 9 · Write the answer underneath the computation as follows: Ans: 49 R 9 |
Summary:
Addition:
Tables:
3 and 4 is 7
Computation: 4 and 8 is 12
Put down the 2 and carry the one
Subtraction:
Tables:
8 take away 4 is 4
Computation: 4 take away 8 - I cannot do
– regroup
– bring over a ten
Multiplication:
Tables:
4 twos are 8
Long multiplication: Circle the tens –multiply by the units
Put down the zero etc.
Division:
Tables:
6 divided by 2 is 3
Computation: 2 into 7 goes three times remainder 1
3 into 2 won’t go – carry the two