To do:We have to express the given numbers as cm using decimals.Solution:We know that, $1\ cm=10\ mm$This implies, $1\ mm=\frac{1}{10}\ cm$Therefore, (a) $2\ mm=2\times\frac{1}{10}\ cm$$=\frac{2\times1}{10}\ cm$$=\frac{2}{10}\ cm$$=0.2\ cm$(b) $30\ mm=30\times\frac{1}{10}\ cm$$=\frac{30\times1}{10}\ cm$$=\frac{30}{10}\ cm$$=3.0\ cm$(c) $116\ mm=116\times\frac{1}{10}\ cm$$=\frac{116\times1}{10}\ cm$$=\frac{116}{10}\ cm$$=11.6\ cm$(d) $2\ mm=2\times\frac{1}{10}\ cm$$=\frac{2\times1}{10}\ cm$$=\frac{2}{10}\ cm$$=0.2\ cm$ This implies, $4\ cm\ 2\ ... Read More

To do:We have to find between which two whole numbers on the number line the given numbers lie.Solution:(a) $0

As given, $x=$position at $t$ time$x=t^2-2t$So, velocity $v=\frac{dx}{dt}=2t-2$Let's check the sign of velocity at different time intervals.At $t=0$, $v=-2\ unit/s$At $t=1\ s$, $v=2\times1-2=0\ unit/s$At $t=2\ s$, $v=2\times2-2=2\ unit/s$At $t=0$, $x=0$At $t=1\ s$, $x=1^2-2\times 1=1-2=-1$At $t=2\ s$, $x=2^2-2\times2=4-4=0$Thus, we can say that at first $1\ s$, the object moves $1\ unit$ ... Read More

To do:We have to find the measure of (i) a right angle(ii) a straight angle Solution:(i) The measure of a right angle is $90^o$.(ii) The measure of a right angle is $180^o$.

To do:We have to find whether the given statements are true or false.Solution:(a) The measure of an acute angle is less than $90^o$Therefore, the given statement is true.(b) The measure of an obtuse angle is more than $90^o$ but less than $180^o$Therefore, the given statement is false.(c) The measure of ... Read More

To do:We have to write the measures of(a) some acute angles(b) some obtuse anglesSolutions: (a) An acute angle is an angle less than $90^o$.Therefore, the measures of some acute angles are $89^o, 43^o$.(b) An obtuse angle is an angle greater than $90^o$.Therefore, the measures of some obtuse angles are $91^o, 137^o$.Read More

To do:We have to measure the angles given using the Protractor and write the measures. Solution:Using the Protractor, (a) The measure of the angle is $45^o$(b) The measure of the angle is $120^o$(c) The measure of the angle is $90^o$(d) The measures of the angles are $60^o, 90^o$ and $130^o$.Read More

To do :We have to write the given decimals in the place value table.Solution :(a) The place value table is as follows, DecimalsHundredsTensOnesTenths19.40194(b) The place value table is as follows, DecimalsHundredsTensOnesTenths0.30003(c) The place value table is as follows, DecimalsHundredsTensOnesTenths10.60106(d) The place value table is as follows, DecimalsHundredsTensOnesTenths205.92059Read More

To do :We have to write the given terms as decimals.Solution :(a) Seven-tenths$\frac{7}{10} = 0.7$Seven-tenths in decimal is 0.7(b) Two tens and nine-tenths$2 \times 10 + \frac{9}{10} = 20 + 0.9 = 20.9$Two tens and nine-tenths in decimal is 20.9(c) Fourteen point six14.6.Fourteen point six in decimal is 14.6.(d) One hundred and two ... Read More

To do:We have to express the given expressions as decimals. Solution: (a) $\frac{5}{10}$$=0.5$Therefore, $\frac{5}{10}=0.5$(b) $3+ \frac{7}{10}=3+0.7$$=3.7$Therefore, $3+\frac{7}{10}=3.7$(c) $200+60+5+\frac{1}{10}=200+60+5+0.1$$=265.1$Therefore, $200+60+5+\frac{1}{10}=265.1$(d) $70+\frac{8}{10}=70+0.8$$=70.8$Therefore, $70+\frac{8}{10}=70.8$(e) $\frac{88}{10}=\frac{80+8}{10}$$=\frac{80}{10}+\frac{8}{10}$$=8+0.8$$=8.8$Therefore, $\frac{88}{10}=8.8$(f) $4 \frac{2}{10}=4+\frac{2}{10}$$=4+0.2$$=4.2$Therefore, $4 \frac{2}{10}=4.2$(g) $\frac{3}{2}=\frac{2+1}{2}$$=\frac{2}{2}+\frac{1}{2}$$=1+0.5$$=1.5$Therefore, $\frac{3}{2}=1.5$(h) $\frac{2}{5}=\frac{2\times2}{5\times2}$$=\frac{4}{10}$$=0.4$Therefore, $\frac{2}{5}=0.4$ (i) $\frac{12}{5}=\frac{10+2}{5}$$=\frac{10}{5}+\frac{2}{5}$$=2+0.4$$=2.4$Therefore, $\frac{12}{5}=2.4$ (j) $3 \frac{3}{5}=3+\frac{3}{5}$$=3+0.6$$=3.6$Therefore, $3 \frac{3}{5}=3.6$(k) $4 \frac{1}{2}=4+\frac{1}{2}$$=4+0.5$$=4.5$Therefore, $4 \frac{1}{2}=4.5$Read More