Vacation with My Nani Maa
Adding and subtracting with a ginladi (bead string), number lines, number grids, and box diagrams, plus magic sums.
- Number bonds: numbers that make 10, 20, and 100
- Adding and subtracting using jumps (1s and 10s)
- Using a number grid to add big numbers quickly
- Box diagrams to understand word problems
- Estimating: is the answer more or less than 100?
🪄 Let’s Begin: Nani’s Magic Trick
Nani puts 10 beads on the table. Pinky hides some under her hand. 6 beads are still showing. Nani smiles: “You’re hiding 4!”
How? Nani knows that 6 and 4 make 10. That’s the magic of number pairs!
➕ Part 1: Adding with Jumps
To add, jump forward on a number line or bead string. Use big jumps of 10 to be fast!
27 + 15: 27 → jump 10 → 37 → jump 3 → 40 → jump 2 → 42
36 + 40: four jumps of 10 → 46, 56, 66, 76
➖ Part 2: Subtracting with Jumps
To subtract, jump backward. Or count up from the smaller number to the bigger one!
53 − 28: count up from 28 → 30 (+2) → 50 (+20) → 53 (+3). 2 + 20 + 3 = 25
🔢 Part 3: The Number Grid
On a 1–100 grid, going down one row adds 10 and going right one square adds 1.
34 + 23 → from 34, go down 2 rows (54), then right 3 (57) → 57.
📦 Part 4: Box Diagrams
Draw a long box for the total, and split it into the parts.
| Total: 100 fruits | |
|---|---|
| Mangoes: 65 | Guavas: ? |
The missing part is 100 − 65 = 35 guavas.
🎯 Part 5: Estimating
Is 150 − 49 more or less than 100? 150 − 50 = 100, and we took away 1 less, so the answer is more than 100 (101).
✏️ Practice Time
Try these on your own first, then check your answer below each question.
📘 NCERT Textbook Activity Help
Hints and answers for the activities in the textbook, page by page. Try each one yourself before looking at the answer!
Page 29 · Magic trickHidden seeds
Adding and subtracting small numbers
Tens frame: (a) 14 (b) 15 (c) 3 (d) 9
Stamp collection
Jumping frog and grasshopper
Q2: 7 → 17, 27, 37, 47, 57, 67, 77, 87, 97 · Q3: 23 → 33, 43, 53, 63, 73, 83, 93 · Q4: 76 → 66, 56, 46, 36, 26, 16, 6
Ants under the leaves: count the numbers hidden between the last number before the leaf and the first number after it.
Jump tables: add 5, 6, or 9 each time, following the arrows (e.g. 34 → 39, 56 → 61, 87 → 82 going back).
Where will they land?
(a) 45 + 34 = 79 (b) 75 + 56 goes past 100, so he moves back: 75 − 56 = 19 (c) 30 + 66 = 96 (d) 89 − 63 = 26 (moving back)
Puzzles and the magic square
(Check puzzle 2 against your book. We solved it using the row and column totals.)
The blue total and the red total are the same, 45 (1 + 2 + … + 9).
Magic square (every line adds up to 15): 8 3 4 / 1 5 9 / 6 7 2
Radishes, carrots, and apples
Solve with box diagrams
Game to 100: try to reach 89 (then any number from 1–10 can’t get your friend to 100, and you win next turn).
Estimate
Less than 100: 68 − 26 = 42 · 109 − 80 = 29 · 63 + 26 = 89 · 134 − 56 = 78 · 20 + 41 = 61 · 156 − 65 = 91
👨👩👧 Tips for Parents
- Play Nani’s hidden-seeds trick with 10 or 20 beans.
- Make a bead string with 100 beads, changing colour every 10.
- Ask: “I had ₹50 and spent ₹23. What’s left?”