Page 64 - Touchpad Mathematics_Ver1.0_C4

Subtraction with regrouping

Example 1. Subtract 1351 from 2089.
Solution.

Step 1. Subtract the ones. 9 – 1 = 8 ones Th H T O
Step 2. Subtract the tens. 8 – 5 = 3 tens
Step 3. Subtract the hundreds. 0 hundreds < 3 hundreds, 1 10
so, regroup thousands and hundreds. 2 0 8 9
2 thousands 0 hundreds = 1 thousand 10 hundreds – 1 3 5 1

Now, 10 – 3 = 7 hundreds.
Step 4. Subtract the thousands. 1 – 1 = 0 thousands 0 7 3 8

So, 2089 – 1351 = 738.

Example 2. Find the difference of 9544 and 7659.
Solution.
Step 1. Subtract the ones. 4 ones < 9 ones, so, regroup tens
and ones. Th H T O

4 tens 4 ones = 3 tens 14 ones 14 13
Now, 14 – 9 = 5 ones. 8 4 3 14
Step 2. Subtract the tens. 3 tens < 5 tens, so, regroup 9 5 4 4
hundreds and tens.

5 hundreds 3 tens = 4 hundreds 13 tens – 7 6 5 9
Now, 13 – 5 = 8 tens. 1 8 8 5

Step 3. Subtract the hundreds. 4 hundreds < 6 hundreds, so,
regroup thousands and hundreds.

9 thousands 4 hundreds = 8 thousands 14 hundreds
Now, 14 – 6 = 8 hundreds.

Step 4. Subtract the thousands. 8 – 7 = 1 thousand
So, 9544 – 7659 = 1885. Interesting Facts

Subtracting 10, 100 and 1000 from a number • Subtracting 0 from any
number gives that number
When 10, 100 and 1000 are subtracted from a itself.
number the digit in its tens, hundreds and thousands 12 - 0 = 12 187 - 0 = 187
place respectively decreases by 1. • Subtracting a number from
Examples. a. 235 – 10 = 225 itself results in zero.
15 - 15 = 0 239 - 239 = 0
• Subtracting 1 from a number
b. 5701 – 100 = 5601 gives the predecessor of the

number.
c. 9876 – 1000 = 8876 55 - 1 = 54 120 - 1 = 119

62 Mathematics 3