Page 42 - ICSE Math 4

Subtraction Facts Mental Maths

• If 0 is subtracted from a number, the result is Find the following.
the number itself. (a) 246 – 0 (b) 401 – 401

For example, 1,436 – 0 = 1,436. (c) 378 – 100 (d) 467 – 1
• If 1 is subtracted from a number, the result is (e) 372 – 100 (f) 934 – 10
the predecessor of that number.

For example, 8,234 – 1 = 8,233.
• If a number is subtracted from itself, the result is 0.
For example, 5,324 – 5,324 = 0.
• The order of numbers in subtrac on cannot be changed.

For example, 2,365 – 1,423 = 942 but 1,423 – 2,365 is not possible as 1,423 < 2,365.

Exercise 4.2

1. Subtract the given numbers.
(a) 459 from 2,736 (b) 385 from 8,624 (c) 816 from 7,921

(d) 5,287 from 7,559 (e) 5,263 from 9,341 (f) 7,492 from 8,636
(g) 1,368 from 2,847 (h) 2,526 from 4,835 (i) 7,389 from 9,806

2. Find the following diff erences.

(a) 9,657 – 8,419 (b) 6,789 – 2,862 (c) 7,985 – 4,658
(d) 5,306 – 1,212 (e) 7,926 – 4,728 (f) 9,257 – 3,583

Subtraction Using Expanded Form

To subtract numbers using the expanded form, we follow the given steps.
• Write each number in the expanded form.

• Subtract the values at each place.
• Find the sum of the subtracted values.

Example 3: Subtract 6,254 from 8,795 using the expanded form.
Solu on: Step 1: Expanded Form
8,795 = 8,000 + 700 + 90 + 5

6,254 = 6,000 + 200 + 50 + 4
Step 2: Th H T O Thousands Hundreds Tens Ones

8 7 9 5 8000 700 90 5

– 6 2 5 4 – 6000 – 200 – 50 – 4

2000 500 40 1

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