E Q U A L CONCEPT

Developed byIvan Seneviratne

EQUAL CONCEPT

The longer bar has the same length as the sum of the 2 shorter bars. Therefore, to find the length of the unknown shorter bar, you need to subtract 8 from 15.

Find the missing number in the blank.Find the missing number in the blank.

8 +8 + ____________ = 15= 15

8 ?

15

15 – 8 = 7

The unknown value is 7.

7

A. _____ + 9 = 17

B. 163 + _____ = 399

C. 7613 695 = 8308

Try theseTry these

EQUAL CONCEPT

PRACTICE

A. ___ + 9 = 17

9?

17

?

399

163

695

8308

7613

SolutionsSolutions

C.C. 7613 695 7613 695 = 8308= 8308

88 17 - 9 = 17 - 9 = 88

B. 163 + ___ B. 163 + ___ = 399 = 399 399 - 163 = 399 - 163 = 236236

236236

++

EQUAL CONCEPT

Find the missing number in the blank.

_____ - 7 = 12

12

The longer bar has the same length as the sum of the 2 shorter bars. Therefore, to find the length of the unknown longer bar, you need to add 7 to 12. 12 + 7 = 19

The unknown value is 19.

7 ?

EQUAL CONCEPT

A. _____ - 8 = 17

B. 163 - _____ = 87

C. 3101 1095 = 2006

Try theseTry these

EQUAL CONCEPT

PRACTICE

A. ___ - 8 = 17

8

?

17

? 87

163

1095 2006

3101

SolutionsSolutions

C.C. 3101 1095 3101 1095 = 2006= 2006

2525 8 + 17 = 8 + 17 = 2525

B. 163 - ___ B. 163 - ___ = 87= 87 163 - 87 = 163 - 87 = 7676

7676

--

EQUAL CONCEPT

PRACTICE

EQUAL CONCEPT

After selling 168 tickets,

?

352168

James still had 352 James still had 352 tickets left.tickets left.How many tickets did James have at How many tickets did James have at

first?first?

To find the number of tickets James had at first, you need to add 352 to 168.

168 + 352 = 520

James had 520 tickets at the beginning.

There were 23 fish balls in a bowl.

23

?

7 5

How many fish balls were left in the How many fish balls were left in the bowl?bowl?

Norman ate 7 fish Norman ate 7 fish balls. balls.

Daniel ate 5 fish Daniel ate 5 fish balls.balls.

From the model, you can write down the following equation.

23 - 7 - 5 = 11There were 11 fishballs left in the

bowl.

EQUAL CONCEPT

1. 16 boys and 13 girls took part in a walkathon. If 5 teachers joined them, how many people took part in the walkathon?

Try theseTry these

EQUAL CONCEPT

PRACTICE

1. 16 boys and

16 + 13 + 5 = 34

?

16 13 5

SolutionsSolutions

how how many people took part in the walkathon? many people took part in the walkathon? If 5 teachers joined If 5 teachers joined

them, them,

13 girls took part in a 13 girls took part in a walkathon.walkathon.

There were 34 people who took part in the walkathon.

EQUAL CONCEPT

PRACTICE

2. A clerk was sent to deliver 155 books to a bookshop. On the way, 27 books were destroyed in the rain and 52 books were crumpled. How many books were in good condition?

Try these

EQUAL CONCEPT

PRACTICE

How many books were in good condition?

27 52

27 + 52 = 79

155 - 79 = 76

SolutionsSolutions2.2. A clerk was sent to deliver 155 books to a A clerk was sent to deliver 155 books to a

bookshop. bookshop. On the way, 27 books were destroyed in On the way, 27 books were destroyed in the rainthe rain

and 52 books were and 52 books were crumpled. crumpled.

155

?

There were 76 books in good condition.

EQUAL CONCEPT

PRACTICE

3. In a week, a fruit seller sold 520 apples during weekdays and 798 apples during weekend. If he threw away 57 rotten apples and had 245 apples left, how many apples did he have at first?

Try theseTry these

EQUAL CONCEPT

PRACTICE

3. In a week,

520 798 57 245

The fruit seller had 1620 apples at the beginning.

SolutionsSolutions

?

how many apples did he have at first?how many apples did he have at first?

a fruit seller sold 520 apples during a fruit seller sold 520 apples during weekdaysweekdaysand 798 apples during and 798 apples during

weekend. weekend. If he threw If he threw

away 57 rotten apples and away 57 rotten apples and

had 245 apples had 245 apples left, left,

520 + 798 + 57 + 245 = 1620

EQUAL CONCEPT

PRACTICE

3. In a week,

520

SolutionsSolutions

how many apples did he have at first?how many apples did he have at first?

a fruit seller sold 520 apples during a fruit seller sold 520 apples during weekdaysweekdaysand 798 apples during and 798 apples during

weekend. weekend. If he threw If he threw

away 57 rotten apples and away 57 rotten apples and had 245 apples had 245 apples left, left,

Weekdays

798Weekend

57Rotten

245Leftover

?

520 + 798 + 57 + 245 = 1620

The fruit seller had 1620 apples at the beginning.

EQUAL CONCEPT

PRACTICE

4. Meling spent of her money on

a blouse and of it on a skirt.

What fraction of her money did she

have left?

Try theseTry these

EQUAL CONCEPT

PRACTICE

29

16

5. Hale had 6 watermelons. She gave

2 watermelons to

Bob and 1 watermelons to Verdun.

How many watermelons had she left?

Try theseTry these

EQUAL CONCEPT

PRACTICE

12

34

This presentation is developed by Ivan Seneviratne © 2006 purely for personal use.ivanthexplorer@yahoo.co.uk