Chapter 6 — Decoration for Festival

It is about adding and subtracting two-digit numbers. The chapter uses a festival decoration story with garlands and flowers, blocks, a bead string called ginladi, and a number line to help children understand these operations.

Each garland holds 10 flowers, so garlands stand for tens and loose flowers stand for ones. When children add garlands from two people, they are really adding the tens and ones of two numbers.

A ginladi is a bead string used as a counting tool. Children slide beads forward to add and slide them backward to subtract, making it a hands-on way to count without writing numbers.

Children start at the first number on the number line and jump forward by tens and then ones to land on the answer. For example, 23 + 14 is solved by jumping +10 from 23 to 33, then +4 to reach 37.

Regrouping means that when the ones digits add up to 10 or more, the extra ten is moved to the tens column. For example, in 36 + 47, 6 + 7 = 13 ones, so 1 ten is carried over and 3 ones remain, giving 83 altogether.

They start at the bigger number and jump backward. For 19 − 15, they jump back 10 steps to 9, then back 5 more steps to reach 4.

When there are not enough loose flowers to give away, a garland (10 flowers) is untied to get 10 extra loose flowers. This is the same as borrowing 1 ten in the standard subtraction method.

Jyoti has 46 flowers and gives away 18. She opens 1 garland to get 16 loose flowers, gives 8 away and keeps 8, then subtracts 1 ten from the remaining 3 tens to keep 2 garlands. She is left with 28 flowers.

A fact family shows how three numbers are related by addition and subtraction. For the numbers 20, 30, and 50: 20 + 30 = 50, 30 + 20 = 50, 50 − 30 = 20, and 50 − 20 = 30.

Mahi and Isha combine their sets of tens and ones blocks to find a total. It shows children that combining blocks is the same as adding two-digit numbers and introduces the idea of regrouping when ones exceed 9.

In an addition pyramid each number is the sum of the two numbers below it, while in a subtraction pyramid each number is the difference. Children fill in the missing numbers in these triangles to practise both operations.

Aman and Avni need to complete 20 skips. If Aman skipped 14 times, children find how many more he needs by solving 20 − 14 and checking it with 14 + __ = 20. It shows the link between addition and subtraction.

The chapter includes problems about runs scored in cricket, colour pencils gifted, marbles collected, money spent at a fair, passengers in a bus, diyas made and sold, shells collected, bangles sold, and balloons that burst.

The chapter says children may use any method they prefer — ginladi, number strip, number block, or moti mala — to find answers, encouraging flexible thinking rather than one fixed method.