Level 1
When rounding to the nearest ten, look at the ones digit.
If the digit is below 5 (0, 1, 2, 3 or 4) we round down.
If the digit is 5 or higher (5, 6, 7, 8 or 9) we round up.
Have a look at how the numbers below have been rounded up and down:
21 - Round down to 20
16 - Round up to 20
42 - Round down to 40
97 - Round up to 100
53 - Round down to 50
35 - Round up to 40
Let's practise estimating the product.
Question
Round the first factor to the nearest ten, then multiply.
16 x 2
Solution
16 - Round to 20
Multiply 20 x 2 = 40
The answer is 40.
Are you ready to start the activities? Let's go!