Page 60 - Start Up Mathematics_1
P. 60
Addition of Three 3-Digit Numbers
Add three 3-digit numbers by following the same steps that we follow to add
two 3-digit numbers.
Look at the given example.
H T O
Step 1: Add the ones of the first two numbers.
1 2 3
3 + 2 = 5
3 1 2
Add the sum 5 to the ones of the third number.
+ 4 4 3 5 + 3 = 8
8
H T O
Step 2: Add the tens of the first two numbers.
1 2 3
2 + 1 = 3
3 1 2
Add the sum 3 to the tens of the third number.
+ 4 4 3 3 + 4 = 7
7 8
H T O
Step 3: Add the hundreds of the first two numbers.
1 2 3
1 + 3 = 4
3 1 2
Add the sum 4 to the hundreds of the third
+ 4 4 3 number.
8 7 8 4 + 4 = 8
4 Find the sum.
H T O H T O H T O
(a) (b) (c)
1 2 4 3 1 2 2 0 5
2 3 1 1 0 5 3 5 0
+ 4 0 3 + 2 6 1 + 1 2 3
52
