We can estimate the answer to an addition sum by rounding the numbers to the nearest ten **before **we add.

**Example 1**

Estimate the answer to the following sum by rounding the numbers to the nearest ten and then adding.

26 + 47

**Answer**

26 + 47

↓ ↓

30 + 50 = **80**

**Example 2**

Estimate the answer to the following sum by rounding the numbers to the nearest ten and then adding.

94 + 75

**Answer**

94 + 75

↓ ↓

90 + 80 = **170**

*Remember that 7 5 rounds up* to 80,

*3*

**5**rounds up to 40, 2**5**round up to 30 etc.