In this activity, you will learn how to round numbers to the **nearest 100 **in order to estimate the answer to a multiplication.

**Rules for rounding to the nearest 100**

If the tens digit is** less than 50**, the number is **rounded down.**

If the tens digit is **50 or more, **the number is **rounded up.**

Estimate the answer by rounding the numbers to the nearest 100 before adding.

We can ignore the 'ones' digit when rounding a 3 digit number to the nearest 100.

**744 would be rounded down to 700.**

**751 would be rounded up to 800.**

**8264 would be rounded up to 8300**

**Example:**

**242 x 164 = ?**

Round each number first

242 200

164 200

Now calculate: **200 x 200 = ?**

2 x 2 x 100 x 100 = 4 x 10,000 = **40,000**