NCERT Solutions for Class 4th Maths Chapter 13 Constructing Tables — Constructing Tables
Book page 186 Updated on2026-09-19
Q1.
Recall the times-tables that we created in Grade 3. Now construct a times-15 table. You may use the arrangement given below and split the columns into 10 and 5 for ease of counting, as shown on the previous page. (1 × 15 = ___, 2 × 15 = ___, … 10 × 15 = ___)The pebble arrangement printed on page 186 — 15 pebbles across and 10 rows down.
Answer
The 10 x 15 pebble arrangement, with each row split into 10 and 5.
Take one row at a time. Each row is 10 pebbles and 5 pebbles.
10 × part
5 × part
Answer
1 × 15
10
5
15
2 × 15
20
10
30
3 × 15
30
15
45
4 × 15
40
20
60
5 × 15
50
25
75
6 × 15
60
30
90
7 × 15
70
35
105
8 × 15
80
40
120
9 × 15
90
45
135
10 × 15
100
50
150
So the times-15 table is: 15, 30, 45, 60, 75, 90, 105, 120, 135, 150
Why it happens: Every new row adds one more 10 and one more 5, that is 15 more pebbles each time.
Q2.
1. What patterns do you see in this table?The pebble arrangement printed on page 186 — 15 pebbles across and 10 rows down.The times-15 table printed on page 186, with every answer still to be filled in.
Answer
Three patterns are easy to see.
The ones digit goes 5, 0, 5, 0, 5, 0 … again and again.
Each answer is 15 more than the one before it.
Every second answer (30, 60, 90, 120, 150) is a multiple of 30 — it is double the one two steps back’s neighbour.