In this activity, we will practise rounding numbers to the **nearest 1,000, 10,000 and 100,000 **in order to estimate the answer to a multiplication.

**Rules for rounding to the nearest 1,000**

To round to the nearest 1,000, look at the hundreds digit.

If the hundreds digit is 5 or more, round up.

If the hundreds digit is 4 or less, round down.

7,434 would be rounded** down **to 7,000.

9,981 would be rounded **up **to 10,000.

12,678 would be rounded **up **to 13,000.

**Rules for rounding to the nearest 10,000**

To round to the nearest **10,000 **look at the thousands digit.

If the thousands digit is 5 or more, round up.

If the thousands digit is 4 or less, round down.

74,434 would be rounded **down **to 70,000.

96,981 would be rounded** up **to 100,000.

125,678 would be rounded** up **to 130,000.

**Rules for rounding to the nearest 100,000**

To round to the nearest **100,000,** look at the ten thousands digit.

If the ten thousands digit is 5 or more, round up.

If the ten thousands digit is 4 or less, round down.

742,434 would be rounded **down **to 700,000.

968,981 would be rounded** up **to 1,000,000.

185,678 would be rounded** up** to 200,000.

**Example:**

**2,624 x 1,122 = ?**

Round each number to the nearest 1,000 first

2,624 3,000

1,122 1,000

Now calculate: **3,000 x 1,000 = ?**

3 x 1 x 1,000 x 1,000 =

3 x 1,000,000 = **3,000,000 (3 million)**

Top tip for multiplying large numbers with lots of zeros!

Remove the zeros, do the calculation and then put the zeros back!

3,000 x 1,000: remove the six zeros and do 3 x 1 = 3

Add the zeros back: 3,000,000

Are you happy with all this?

Let's get started.