Adding And Subtracting Decimal Numbers
Transcript
00:00Hi kids!
00:03We already learned what are decimal numbers.
00:07Today we will learn addition and subtraction of decimals.
00:12So let's get started.
00:17Here we have two decimal numbers.
00:2123.03, 20.5
00:26Now let's learn how to add them.
00:31Write the bigger number and the smaller in such a way that decimal points are aligned.
00:39Then you can add zeros to places where there are no numbers.
00:45Like you can add 0 at 100's place after 5.
00:51As placing zeros to the right of decimal does not change the number.
00:580.5 and 0.50 and 0.500 are all same numbers.
01:07Now start adding from the rightmost digit.
01:113 plus 0 equals 3, so write 3 below the 100's place in sum.
01:19Now add the 10's place digits.
01:230 plus 5 equals 5.
01:27Write 5 in the sum below the 10's digit.
01:32Now put decimal in the sum.
01:36Now add the whole numbers as you simply add.
01:403 plus 0 equals 3, 2 plus 2 equals 4.
01:46So our sum is 43.53.
01:52Now let's take another example.
01:55Here we have two decimal numbers.
01:59Now let's add them.
02:02First of all, write the numbers in such a way that decimal points are aligned.
02:08And you can add zeros too.
02:11You can write 123.6 as 123.60.
02:20As appending zeros in the end of decimal numbers do not change the numbers.
02:26Remember, only in case of decimal numbers.
02:311 and 10 are not same.
02:35But, 0.1 and 0.10 are same.
02:40You can write 45.69 as 045.69.
02:49As appending zeros before any number does not change the number.
02:541 and 01 are same.
02:581.5 and 01.5 are same numbers.
03:04Now let's add the numbers.
03:07Start adding from the rightmost digit.
03:119 plus 0 equals 9.
03:15So write 9 below hundredths place in sum.
03:20Now add the tenths place digits.
03:246 plus 6 equals 12.
03:27Write 2 in the sum below the tenths digit.
03:31And give one carryover to next digit, that is ones place digit.
03:35Now put decimal in the sum.
03:39Now add the whole numbers as you simply add.
03:431 plus 3 plus 5 equals 9.
03:48Write 9 in sum below ones place.
03:522 plus 4 equals 6.
03:56So write 6 in sum below tens place.
04:001 plus 0 equals 1.
04:05Write 1 in sum below hundredths place.
04:10So kids, 169.29 is our answer.
04:17Now let's learn how to subtract decimal numbers.
04:22We have to subtract 65.80 from 206.60.
04:32Now let's learn how to subtract them.
04:35First of all, write the numbers in such a way that decimal points are aligned.
04:41And bigger number always above the smaller number.
04:45Now you can append zeros too.
04:48You can write 206.6 as 206.60.
04:56You can write 65.80 as 065.80.
05:02Now start subtracting as you subtract the whole numbers.
05:080 subtract 0 equals 0.
05:13So write 0 below hundredths place in difference.
05:18Now you cannot subtract 8 from 6.
05:22So borrow 1 from ones place digit.
05:26Plus 6 make it 5.
05:29Get borrow to 6 at tens place.
05:33Now subtract 8 from 16.
05:3716 subtract 8 equals 8.
05:42So we get 8.
05:45Now write 8 in difference below the tens digit.
05:52Now put decimal in the difference.
05:555 minus 5 equals 0.
05:58Write 0 in difference below ones place.
06:03We cannot subtract 6 from 0.
06:07So borrow 1 from digit at hundredths place.
06:11That is 2.
06:13Plus 2 make it 1.
06:17And get borrow 1 to 0.
06:20Now 10 minus 6 equals 4.
06:23So write it in difference below tens place.
06:271 minus 0 equals 1.
06:31Write 1 in hundredths place in difference.
06:35So kids 206.60 minus 65.80 equals 140.80.
06:47We have learned today how we can add and subtract our decimal numbers.
06:54Now you may go ahead and take a quiz to learn more.
06:58Bye bye.