##### Theory: Ordinal Numbers.

Ordinal numbers tell the position or order of objects.

If ten students ran a race, the student that ran the fastest would be in first place, the next student would be in second place, and then there would be third, fourth, fifth, sixth, seventh, eighth, ninth and tenth places.

The first ten ordinal numbers are:

First Second Third Fourth Fifth Sixth Seventh Eighth Ninth Tenth

The next ten ordinal numbers are:

Eleventh Twelfth Thirteenth Fourteenth Fifteenth Sixteenth Seventeenth Eighteenth Nineteenth Twentieth

##### Solutions from the Previous Issue:

Proposed by Alexandru Rosu   St.John  Bosco School, Grade 2 Brampton, Ontario,  Canada

1.        2 5 + 7  6 - 1 =

Solution:       2 5+ 7 6 – 1 =

10 + 42 – 1 =

52 – 1 = 51

2.        2 (19 - 4) - 3 5 =

Solution:       2 (19 - 4) – 3 5 =

2  15 – 15 =

30 – 15 = 15

3.        6 (7 - 6) - (46 - 44) 3 =

Solution:       6 (7 - 6) - (46 - 44)  3 =

6 1 - 2 3 =

6 – 6 = 0

4.        2 + 3 (29 - 20) 9 + 1 =

Solution:       2 + 3 (29 - 20) 9 + 1 =

2 + 3 9 9 + 1=

2 + 27 9 + 1=

2 + 3 + 1 = 6

5.        2 (14 + 6) 5 + 9 - 4 =

Solution:       2 (14 + 6) 5 + 9 – 4 =

2 20 5 + 9 – 4 =

40 5 + 9 – 4 =

8 + 9 – 4 =

17 – 4 = 13

6.        (16 - 4) 3 + 18 9 =

Solution:       (16 - 4) 3 + 18 9 =

12 3 + 18 9 =

4 + 18 9 =

4 + 2 = 6

7.        (18 - 2) 21 - (39 - 11) =

Solution:       (18 - 2)  21 - (39 - 11) =

16 21 – 28 =

336 – 28 = 308

Proposed Exercises:

Calculate:

1.        700 + 202=

2.        200 + 300 =

3.        ? + 137 = 297