Addition
Traditional method or column addition
Requires you to understand that the number such as 385 is in fact three 100’s eight 10’s and five 1’s.
Or 300+80+5
And this place value system is called the decimal system.
Remember this is better than adding pounds shillings and pence.
NOTE:
d = pennies = 12 pennies in a shilling
S = shillings = 20 shillings in a pound
£ = Pound = 240 pence (12×20=240)
and 8d+7d+10d=25d or 2 shillings and 1d
and 4S+5S+3S and 2S carried over is 14 shillings
Example 1
398+427
3 | 9 | 8 |
4 | 2 | 7 |
8 | 2 | 5 |
Answer: =825
To see this example step by step
Traditional addition
Example 1
398+427
3 | 9 | 8 | |||
+ | 4 | 2 | 7 | ||
1 | |||||
3 | 9 | 8 | Add the ones (8 ones +7 ones =15 ones) | ||
+ | 4 | 2 | 7 | Regroup (15 ones =1 ten +5 ones) | |
5 |
1 | 1 | ||||
3 | 9 | 8 | Add the tens (1 ten +9 tens +2 tens =12 tens) | ||
+ | 4 | 2 | 7 | Regroup (12 tens =1 hundred +2 tens) | |
2 | 5 |
1 | 1 | ||||
3 | 9 | 8 | Add the hundreds (1 hundred +3 hundred +4 hundred =8 hundred) | ||
+ | 4 | 2 | 7 | ||
8 | 2 | 5 |
Answer: =825
Example 2
365+297
3 | 6 | 5 |
2 | 9 | 7 |
6 | 6 | 2 |
Answer: =662
To see this example step by step
Traditional addition
Example 2
365+297
3 | 6 | 5 | |||
+ | 2 | 9 | 7 | ||
1 | |||||
3 | 6 | 5 | Add the ones (5 ones +7 ones =12 ones) | ||
+ | 2 | 9 | 7 | Regroup (12 ones =1 ten +2 ones) | |
2 |
1 | 1 | ||||
3 | 6 | 5 | Add the tens (1 ten +6 tens +9 tens =16 tens) | ||
+ | 2 | 9 | 7 | Regroup (16 tens =1 hundred +6 tens) | |
6 | 2 |
1 | 1 | ||||
3 | 6 | 5 | Add the hundreds (1 hundred +3 hundred +2 hundred =6 hundred) | ||
+ | 2 | 9 | 7 | ||
6 | 6 | 2 |
Answer: =662



