Addition , Subtraction , Multiplication

Addittion

The sum is always greater than the numbers being added,Except when one of the numbers being added is 0(zero).

example

3 1 4

When you change the order of numbers while adding,the sum doesn’t change.

14+13=27

13+14=27

• The sum of zero and any number is the same number .

• 21+0=21• 0+33=33

• When you add 1 to a number the answer is the number after.

• 8+1=9• 1+25=26

Adding bigger numbers

• Adding bigger numbers is a lot like adding 3-digit numbers.start with the ones Then move on to the hundreds and so on.

• There were 2392 peoples on the first day of the book fair and 5106 people on the second day. How many people on both the days?

• 2392+5106=?

• Step 1:add the onesTHOUSANDS HUNDREDS TENS ONES

2 3 9 2

5 1 0 6

8

Step 2:add the tens

THOUSANDS HUNDREDS TENS ONES

2 3 9 25 1 0 6

9 8

Step 3:add the hundredsThousands Hundred Tens Ones

2 3 9 2

5 1 0 6

4 9 8

Step 4:add the thousandsThousands Hundreds Tens Ones

2 3 9 2

5 1 0 6

7 4 9 8

Word Problems

• Anagha collects match box covers.She has 96 of them.her friend,Shakti has 19 more than Anagha.How many match box does Shakti have? +1

• 96+19=? 96• +19• 11 5

• There were 728 girls in the girls section.There were 900 boys in the boys section.How many childrens are there in all?

• 900+728=? 900• + 728• 16 2 8

Subtraction

The answer in subtraction is called difference.

Examples

2 1 1

Remember

When we subtract a number from itself , the answer is always 0.

When we subtract zero from a number , the answer is itself.

14-14=012-0=12

Using subtraction

• To find out what was taken away• We use subtraction when we know the

original number and what is left over but need to find out what was taken away.

• Eighteen children were on the swing.Some children went home.there are now five children on the swing.How many children went home?18-?=5

• We can find the answer by subtraction.• 18-5=13 so, 18 – 13 = 5• Ans-13 children went home.

To find out how many more needed

• We use subtraction when we have to find out how many more to be added to get the given number.

• Varuns mother needs 15 apples to make fruit salad.She has 9 apples.How many more does she need? 9+?=15.

• This can be solved using subtraction• 15-9=? 15-9 = 6 so,9+6=15• Ans – Varuns mother needs 6 more apples for the

fruit salad.

Subtracting 3-digit numbers

• Regrouping tens to ones.• Sometimes when you subtract,you may

not have enough ones.You may have to regroup 1 to tens.

• 573 peoples came for exibition in the morning.256 people left in afternoon.How many are still at the exibition? 573-256=?

Step 1.subtract the ones

Hundreds Tens Ones

5 6 7 12 3

2 5 6

6

Step2.subtract the tens

Hundreds Tens Ones

5 6 7 12 3

2 5 6

1 6

Step3.subtract the hundredsHundreds Tens Ones

5 6 7 12 3

2 5 6

3 1 6

Word problems

• Janes book has 77 pages.Last night she read 22 pages.How many more pages to read?

• 7 7• - 2 2• 5 5

Multiplication

When each group has the same number , we use multiplication to find out how many are there in all.

•

2

2 2 6

3groups of 2 each is 6.

3 * 2 = 6

Remember • Any number multiplied by 1 is that number itself• Any number multiplied by 0 is always 0.• The order of numbers being multiplied does not

matter.

Multiplying 3-digit numbers

• Lorries carry motorbikes over long distances.If each lorry can carry 132 motorbikes.How many bikes will 3 such lorries carry ? 132*3=

Step 1.multiply the ones

Hundreds Tens Ones

1 3 2

3

6

Step 2.multiply the tensHundreds tens Ones

1 3 2

3

9 6

Step 3.multiply the hundredshundreds tens Ones

1 3 2

3

3 9 6

Ans – 369 motorbikes would be carried by 3 lorries.

Word problems• 23 buses , each carrying 13 school children were

taken to the book fair.How many children went to the book fair ? 23*13 = 299 2 3

• 1 3• 6 9• 2 3 0• 2 9 9

Revision • 480+309• 723+168• 184+272• 639+384• 376+921• 246+389

Add these sums

Subtract and multiply

• 983-126 132*96• 728*45 895-56• 859-666 300-142• 900-700• 800*69• 231*2

• Done by Kumari Urvashi• 5 C