Page 44 - Mathematics Pre Primer

Addi on of 2-Digit Numbers

Addi on of a 2-Digit Number with a 1-Digit Number

A 2-digit number has 2 places : ones and tens.

2 3

Ones place digit (0)

Tens place digit (T)

When we add a 2-digit number with a 1-digit number, we

first add the ones digit and write the tens digit as it is.

For example,

T O

4 1 1
T = Tens
+ 4 2 3 4 5
O = Ones
4 5

Add by drawing lines :

T O T O T O T O

4 1 6 2 5 5 7 5

2
+ 3 + 6 + 4 + 4

T O T O T O T O

1 1 1 1 5 2 6 0

+ 7 + 4 + 7 + 5
2

Activity
Variation To understand and practise the concept of adding 2 digit numbers.

44 Maths Pre-Primer