## Solving Lesson 7 Page 27 Math Workbook 10 – Kite>

Topic

Write the round number of each of the following approximations:

a) -131 298 with precision $$d = 20$$

b) 0.02298 with precision $$d = 0.0006$$

Solution method – See details

We say $$a$$ is an approximation of $$\overline a$$ with precision $$d$$ if $${\Delta _a} = \left| {a – \overline a } \right| \le d$$

Detailed explanation

a) -131 298 with precision $$d = 20$$

The largest row of precision $$d = 20$$ is tens, so we round -131 298 to hundreds we get the rounded number of -131 298 which is -131 300

b) 0.02298 with precision $$d = 0.0006$$

The largest row of precision is $$d = 0.0006$$ which is ten thousandths, so we round 0.02298 to thousandths we get 0.02298 rounding number 0.023