At the end of this lesson, students should be able to round decimals to the nearest whole number, tenth, hundredth or thousandth.
When you round a decimal, you represent it by a number that the decimal is closest to. Rounding enables you to write a number in a way that suits your purpose. Decimals can be rounded to the nearest whole number, tenth, hundredth, thousandth, etc.
Steps to follow when rounding decimals:
From previous knowledge acquired on the study of decimal number lines;
6.5 is half way between 6 and 7
6.54 is nearer to 7, because it is more than half way between 6 and 7.
6.49 is nearer to 6, because it is less than half way between 6 and 7.
6.501 is more than half way between 6 and 7.
6.498 is less than half way between 6 and 7.
Suppose we are to round these decimals the nearest whole number;
A similar approach is applied when rounding numbers.
Round these numbers to their nearest whole number
a) 7.49 b) 18.91 c) 39.085
Round to 1 decimal place (nearest tenth).
a)0.455 b) 8.99 c) 57.08
Round to the nearest hundredth (2 decimal places)
a) 49.894 b) 12.899 c) 130.007
Round to the nearest thousandth (3 decimal places)
a) 99.9985 b) 18.9063
Unit 10 Lesson 8: Exercise 1
Round these decimals to the nearest whole number.
Unit 10 Lesson 8: Exercise 2
Round to the nearest tenth.
Unit 10 Lesson 8: Exercise 3
Round these decimal numbers to 2 decimal places.
Unit 10 Lesson 8: Exercise 4
Round these to the nearest 1/1000 of a kilometer.
Unit 10 Lesson 8: Exercise 5
Write the decimal equivalent to each fraction to the nearest hundredth.