Chapter 4 — Vacation with My Nani Maa

It is about a vacation story where two children, Chirag and Nandini, visit their grandmother Nani Maa. The chapter uses things they do together — counting seeds, sharing sweets, collecting stamps, picking radishes and apples — to teach addition and subtraction up to 200.

The chapter uses four main tools: a number line (jumping in steps), the ginladi (a bead-based counting tool), bundles and sticks to show tens and ones, and box diagrams that draw the two numbers side by side. Children are encouraged to use more than one method for the same problem.

Nani Maa covers some marbles with a handkerchief and asks the children to figure out how many are hidden when they know the total. It is a fun way to introduce the idea of subtraction — finding an unknown part when the total and one part are known.

The chapter starts with small numbers like 7 + 5 (balushahi sweets) and builds up to two-digit sums like 25 + 36 (radishes), 22 + 30 (stamps), 85 + 67 (apples), and problems that cross 100 such as 124 + 23 + 20 and 150 - 49.

Two players roll two dice to make a two-digit number and move a counter forward or backward on a 1–100 grid by that amount. The first player to land on a number between 91 and 100 wins. It makes adding and subtracting two-digit numbers feel like a board game.

Skip counting means jumping from a number by the same amount each time. In this chapter, a frog and a grasshopper jump on a number line or bead string by 10s, and children also fill tables by jumping by 5, 6, or 9 from different starting numbers to see the pattern.

A magic square is a 3 by 3 grid filled with the numbers 1 to 9 so that every row, column, and diagonal adds up to the same total. Nani Maa finds these puzzles in a newspaper and the children fill in missing numbers to complete the squares.

Estimation helps children develop number sense — a feel for roughly how big an answer should be before doing exact arithmetic. For example, before adding 85 and 67, Nani Maa points out that 80 + 20 is already 100, so the total must be more than 100. This helps children spot mistakes in their own calculations.

The word problems come from everyday life: a shopkeeper selling books on two days, a cricket team scoring runs before and after lunch, a canteen seller counting vadas, and a gardener losing plants. Children must read each situation, decide whether to add or subtract, and then solve it.

The ginladi is a bead tool used in this chapter to add and subtract by sliding beads in groups. For example, to solve 34 + 6 or 42 - 15, children jump beads in convenient chunks (like +10 then -1) rather than counting one by one, which builds mental-math strategies.

Yes, there are three games. The card game asks players to collect three cards that make an addition or subtraction statement. The number grid game uses dice and a 1–100 grid. The race-to-100 game has two players take turns adding numbers between 1 and 10 until someone reaches exactly 100.

Chirag and Nandini are two children who love their grandmother, Nani Maa. The whole chapter is set during their vacation with her, and the maths problems arise naturally from things the three of them do together, like collecting stamps, picking apples, and solving puzzles from the newspaper.