Page 27 - Fun with Mathematics 2

4 -DIGIT ADDITION (WITHOUT REGROUPING)

4
Add 23 5 and 5623.

Step 1. Add the ones digits.
Th H T O 5 ones + 3 ones = 8 ones

2 3 4 5 Write 8 under the ones (O) column.

+ 5 6 2 3 Step 2. Add the tens digits.
4 tens + 2 tens = 6 tens
7 9 6 8 Write 6 under the tens (T) column.

Step 3. Add the hundreds digits.
3 hundreds + 6 hundreds = 9 hundreds
Write 9 under the hundreds (H) column.
4
Step . Add the thousands digits.
2 thousands + 5 thousands = 7 thousands
Write 7 under the thousands (Th) column.
4
The sum of 23 5 and 5623 is 7968.

4-DIGIT ADDITION (WITH REGROUPING)

4
Add 286 and 3137.
Step 1. Add the ones digits.
Th H T O 6 ones + 7 ones = 13 ones

4
1
1
2 8 6 Regroup 13 ones as 1 ten + 3 ones.
+ 3 1 3 7 Write 3 under the ones (O) column.
Carry over 1 to the tens (T) column.
7 4 2 3 Step 2. Add the tens digits.

1 ten (carried over) + 8 tens + 3 tens = 12 tens
Regroup 12 tens as 1 hundred + 2 tens.
Write 2 under the tens (T) column.
Carry over 1 to the hundreds (H) column.
Step 3. Add the hundreds digits.
1 hundred (carried over) + 2 hundreds + 1 hundred
4
= hundreds
4
Write under the hundreds (H) column.
4
Step . Add the thousands digits.
4 thousands + 3 thousands = 7 thousands
Write 7 under the thousands (Th) column.
4
4
The sum of 286 and 3137 is 7 23.

27