Jayashri Bhattacharya and Tarika Dhawan Solutions for Exercise 6: MENTAL MATHS

How many three-digit numbers have $9$ in them?

Write the following in Roman numerals:

The following in Roman numerals: $82$ is $LXXXII$

write $\left(\mathrm{Yes} / \mathrm{No}\right)$

Write the following in Roman numerals:

Convert $15 \mathrm{km} 215 \mathrm{m} 61 \mathrm{cm} 8 \mathrm{mm}$ into millimetres. Write it in words in the Indian system of numeration.

Which digit has its place value and face value same in every number it is present in?

Akash, Vishu, Sohini and Preeti are classmates. Akash is taller than Vishu while Vishu is taller than Sohini. Preeti, who is taller than Vishu and Sohini, is shorter than Akash. Find out who among them is the tallest and the shortest. Also write their names from the tallest to the shortest.

The height of a room is $3$$\mathrm{m}$ $600 \mathrm{cm}$. An insect starts climbing the wall. Every day, it climbs $1$$\mathrm{m}$ $400\mathrm{cm}$ but slides down $200 \mathrm{cm}$. If in $k$ days insect reaches ceiling then find $k$.