Mathematics: Class 3 — Chapter 9: House of Hundreds - II

Numbers can be represented visually using tiles of different values:

• Large square tiles represent Hundreds ($100$).
• Rectangular tiles represent Tens ($10$).
• Small square tiles represent Ones ($1$).

For example, the number $832$ is represented by $8$ hundred-tiles, $3$ ten-tiles, and $2$ one-tiles.

Number lines help visualize the relative positions and order of numbers. Students practice locating numbers such as:

• $530, 540, 628, 696, 590$ on a number line ranging from $500$ to $700$.
• $703, 721, 759, 810, 855, 887$ on a number line ranging from $695$ to $895$.

Finding the boundaries of a number helps in rounding and estimation. For any given number, we can identify its:

• Neighbouring Hundreds: The multiples of $100$ between which the number lies.
• Neighbouring Fifties: The multiples of $50$ between which the number lies.
• Neighbouring Tens: The multiples of $10$ between which the number lies.

Example for $468$:

• Neighbouring Hundreds: $400$ and $500$
• Neighbouring Fifties: $450$ and $500$
• Neighbouring Tens: $460$ and $470$

Using a number line, we can calculate the distance (steps) to the nearest tens or hundreds:

• To reach $650$ from $667$: $667 - 17 = 650$ (Length of steps: $17$)
• To reach $700$ from $667$: $667 + 33 = 700$ (Length of steps: $33$)

Tambola involves filling a grid with numbers between $570$ and $630$ and striking them out based on mathematical clues, such as:

• A number with $4$ as a digit.
• Numbers between $595$ and $605$.
• A number with $1$ as the tens digit.
• Two more than $610$ ($612$).
• $5$ less than $625$ ($620$).

Completing number patterns using skip counting rules:

• Skip counting by $+10$: $720 \rightarrow 730 \rightarrow 740 \rightarrow 750$
• Skip counting by $+100$: $450 \rightarrow 550 \rightarrow 650 \rightarrow 750$
• Skip counting by $+25$: $850 \rightarrow 875 \rightarrow 900 \rightarrow 925$
• Skip counting by $+15$: $830 \rightarrow 845 \rightarrow 860 \rightarrow 875$

Expressing a central number in multiple ways using addition or subtraction sentences:

• For $400$: $290 + 110$, $300 + 100$, $500 - 100$
• For $775$: $750 + 25$, $700 + 75$, $800 - 25$

Matching real-world quantities to appropriate numerical ranges:

• Number of children in your school: $501 - 1000$
• Number of books in your classroom: $51 - 100$
• Number of pages in your mathematics book: $101 - 200$
• Number of stars in the sky: More than $1000$

Solving riddles based on place value and conditions:

• "I have 2 zeroes as digits and am very close to 99" $\rightarrow 100$
• "I have 3 hundreds, 6 tens and 7 ones" $\rightarrow 367$
• "I am century + half century" $\rightarrow 150$
• "I come between 400 and 450, and I have 5 as a digit" $\rightarrow 425$

Exploring unique properties of numbers:

• Consecutive ascending digits: $123, 345, 789$
• Consecutive descending digits: $321, 876$
• Twin digits: $11, 22, 33$
• Triplet digits: $111, 222, 333$
• Palindromes (same left-to-right and right-to-left): $353, 868$
• Numbers with zeroes: $210, 404, 800$

Forming numbers using limited resources:

• Using six paper slips of values $100$, $10$, or $1$ to form numbers like $231$ ($2$ of $100$, $3$ of $10$, $1$ of $1$).
• Creating 2-digit and 3-digit numbers using only the digits $3$ and $8$ (e.g., $38, 83, 338, 388, 883$).