At the end of this lesson, students should be able round decimal numbers to the nearest whole number, tenth, hundredth or thousandth.
Rounding a decimal means representing it by a number to which the decimal is nearest to.
Rounding a decimal numbers allows us to write the number in a way to suit our purposes. Decimals can be rounded to the nearest whole number, tenth, hundredth, thousandth, etc.
If we are to round to the nearest whole number:
a) 3.54 = 4 b) 3.49 = 3 c) 3.504 = 4 d) 3.497 = 3
A similar idea is what we use to round figures. Below are some examples:
Round these decimal numbers to the nearest whole number.
a) 2.63 b) 13.429 c) 238.532
Round to the nearest tenth (1 decimal place):
a) 4.829 b) 13.499 c) 6.952
Round to the nearest hundredth (2 decimal places)
a) 4.826 b) 267.199 c) 10.841
Round to the nearest thousandth (3d.p)
a) 2.8469 b) 18.2195 c) 9.1111
a) 2.8469 = 2.847
b) 18.2195 = 18.220
c) 9.1111 = 9.111