Mathematics: Class 1 — Chapter 5: How Many?

• Children: $4 \text{ children} + 2 \text{ children} = 6 \text{ children}$ ($4 + 2 = 6$)
• Tops: $3 \text{ tops} + 1 \text{ top} = 4 \text{ tops}$ ($3 + 1 = 4$)
• Ants: $3 \text{ ants} + 2 \text{ ants} = 5 \text{ ants}$ ($3 + 2 = 5$)
• Pencils: $4 \text{ pencils} + 3 \text{ pencils} = 7 \text{ pencils}$ ($4 + 3 = 7$)
• Balls: $6 \text{ balls} + 2 \text{ balls} = 8 \text{ balls}$ ($6 + 2 = 8$)
• Stones: $7 + 1 = 8$

Discussion questions for counting:

• How many brothers and sisters do your parents have altogether?
• How many family members do you and your friend have altogether?
• How many fingers do you have in both your hands and feet?
• How many numbers can you count on your fingers?

Practice addition using fingers:

• $4 + 3 = 7$
• $3 + 2 = 5$
• $5 + 3 = 8$
• $4 + 0 = 4$
• $4 + 4 = 8$

Roll two dice together and find the total number of dots on both dice. Compare scores with a friend to see who scores more.

Example game between Kishore and Nitya:

• Kishore: $5 \text{ and } 1 = 6$ | Nitya: $4 \text{ and } 1 = 5$ (Kishore wins)
• Kishore: $2 \text{ and } 2 = 4$ | Nitya: $1 \text{ and } 5 = 6$ (Nitya wins)
• Kishore: $1 \text{ and } 4 = 5$ | Nitya: $4 \text{ and } 4 = 8$ (Nitya wins)
• Kishore: $3 \text{ and } 1 = 4$ | Nitya: $1 \text{ and } 3 = 4$ (Tie)
• Kishore: $4 \text{ and } 2 = 6$ | Nitya: $4 \text{ and } 3 = 7$ (Nitya wins)

Colouring beads on a string to represent addition:

• $3 + 4 = 7$
• $4 + 2 = 6$
• $5 + 4 = 9$
• $2 + 7 = 9$
• $7 + 3 = 10$

Using a number strip to hop forward and find the sum:

• $4 + 2 = 6$
• $3 + 2 = 5$
• $5 + 3 = 8$
• $6 + 3 = 9$

Addition can be written horizontally or vertically:

• Vertical: $\begin{array}{r} 2 \\ + 3 \\ \hline 5 \end{array}$ is the same as Horizontal: $2 + 3 = 5$
• Vertical: $\begin{array}{r} 5 \\ + 1 \\ \hline 6 \end{array}$ is the same as Horizontal: $5 + 1 = 6$
• Vertical: $\begin{array}{r} 3 \\ + 3 \\ \hline 6 \end{array}$ is the same as Horizontal: $3 + 3 = 6$
• Vertical: $\begin{array}{r} 9 \\ + 1 \\ \hline 10 \end{array}$ is the same as Horizontal: $9 + 1 = 10$

Finding different pairs of numbers that add up to a target sum:

• Target Sum 8: $7+1$, $1+7$, $2+6$, $3+5$, $5+3$
• Target Sum 7: $6+1$, $1+6$, $5+2$, $2+5$
• Target Sum 9: $1+8$, $2+7$, $3+6$, $5+4$ (Inspired by the Wheel in Konark Sun Chariot)
• Target Sum 5: $1+4$, $2+3$, $3+2$, $4+1$

A countdown poem showing subtraction by $1$ at each bus stop:

• Start with $5$ children. One steps out $\rightarrow$ $5 - 1 = 4$ left.
• $4$ children. One steps out $\rightarrow$ $4 - 1 = 3$ left.
• $3$ children. One steps out $\rightarrow$ $3 - 1 = 2$ left.
• $2$ children. One steps out $\rightarrow$ $2 - 1 = 1$ left.
• $1$ child. Last steps out $\rightarrow$ $1 - 1 = 0$ left.

• Frogs: $6 \text{ frogs} - 2 \text{ jumped away} = 4 \text{ left}$ ($6 - 2 = 4$)
• Balloons: $7 \text{ balloons} - 2 \text{ flew away} = 5 \text{ left}$ ($7 - 2 = 5$)
• Bananas: $9 \text{ bananas} - 6 \text{ took away} = 3 \text{ left}$ ($9 - 6 = 3$)
• Pots: $3 \text{ pots} - 1 \text{ broke} = 2 \text{ left}$ ($3 - 1 = 2$)
• Ladoos: $7 \text{ ladoos} - 4 \text{ eaten} = 3 \text{ left}$ ($7 - 4 = 3$)
• Balls: $7 \text{ balls} - 3 \text{ took away} = 4 \text{ left}$ ($7 - 3 = 4$)

• Manisha has $9$ bananas. She ate $3$ bananas. How many bananas are left?
  Answer: $9 - 3 = 6$ bananas.
• There are $8$ butterflies on the flowers. $5$ butterflies flew away. How many butterflies are left?
  Answer: $8 - 5 = 3$ butterflies.

Using a number strip to jump backwards for subtraction:

• Jump $3$ steps back from $9$: $9 - 3 = 6$
• Jump $4$ steps back from $7$: $7 - 4 = 3$

• $8 - 2 = 6$
• $7 - 3 = 4$
• $9 - 5 = 4$
• $6 - 3 = 3$
• $5 - 1 = 4$
• $4 - 2 = 2$