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E:\Working\Orange_Education\Math_Genius_4\Open_Files\Chap-03
\ 30-Sep-2025 Bharat Arora Proof-9 Reader’s Sign _______________________ Date __________
Let us learn this in detail.
To multiply a number by tens (10, 20, 30, …), we multiply the number by the
digit in the tens place and write a 0 at the end of the product.
Examples: (a) 248 × 10 = 2480 (b) 367 × 20 = 7340 (c) 4123 × 30 = 123690
To multiply a number by hundreds (100, 200, 300, ....), we multiply the number by
the digit in the hundreds place and write two 0s (00) at the end of the product.
Examples: (a) 438 × 100 = 43800 (b) 164 × 200 = 32800 (c) 1245 × 300 = 373500
To multiply a number by thousands (1000, 2000, 3000, ....), we multiply the
number by the digit in the thousands place and write three 0s (000) at the end
of the product.
Examples: (a) 7 × 5000 = 35000 Think Tank Critical Thinking
(b) 38 × 1000 = 38000 A bundle of ten-rupee notes
contains 100 notes. How much money
(c) 264 × 2000 = 528000 is there in 17 such bundles?
practice time 3D
1. Fill in the blanks.
(a) 37 × 10 = ____ (b) 268 × 100 = ____ (c) 3412 × 30 = ____
(d) _____ × 1000 = 93000 (e) 246 × ____ = 2460 (f) 43 × 400 = ____
2. Find the product of the following.
(a) 372 × 20 (b) 45 × 30 (c) 578 × 40 (d) 478 × 800
(e) 274 × 100 (f) 372 × 2000 (g) 278 × 300 (h) 48 × 4000
properties of Multiplication
1. Multiplicative Property of 0: When a number is multiplied by 0, the product is
always 0.
Examples: (a) 8 × 0 = 0 (b) 12 × 0 = 0 (c) 481 × 0 = 0
2. Multiplicative Property of 1: When a number is multiplied by 1, the product is
the number itself.
Examples: (a) 7 × 1 = 7 (b) 13 × 1 = 13 (c) 340 × 1 = 340
3. Order Property: The product of two numbers does not change when we change
the order of the numbers.
Examples: 7 × 8 = 56 and 8 × 7 = 56 So, 7 × 8 = 8 × 7.
same
The order property is also known as the Commutative Property of multiplication.
Mathematics-4 59
