Activity 2: Adding and Subtracting
This activity may be used independently, in pairs, or as a class activity on a range of digital devices such as an interactive whiteboard, laptop, i-pad, etc.
Purpose
The purpose of this activity is to recognise and order numbers from 1 to 100, and to practice addition and subtraction facts by using the hundreds board as a number line.
Activities
Using the hundreds board, students could be asked to:
-
Do addition and subtraction.
Show how to add or subtract the tens first by counting up or down, then the ones by counting left or right. -
Look for addition and subtraction patterns.
Ask the students to find 4+9, 14+9, 24+9, 34+9, 64+9. Describe the pattern.
15-7, 25-7, 45-7, etc. describe what these answers have in common. Find other patterns. -
Play Bingo.
The teacher calls problems and students select answers until a row or column is filled and student calls 'Bingo'.- A 5x5 square is selected and outlined to produce the bingo board.
- Example set of questions for board with a 5 by 5 square beginning at 1:
| 6 + 5 | 16 - 1 | 5 more than 40 | 19 - 6 | 3 less than 34 |
| 45 - 2 | 18 + 5 | 3 + 0 | 42 + 2 | How many tens in 53 |
| 28 + 5 | 10 – 9 | 7 + 5 | 11 + 11 | Place value of 4 in 34 |
| 12 + 13 | 13 - 11 | 8 more than 6 | 21 + 21 | 10 less than 51 |
| 31 + 4 | 12 + 12 | 25 – 4 | 16 + 16 | 6 less than 40 |
- Example set of questions for board with a 5 by 5 square beginning at 15:
| 13 + 13 | 7 + 8 | 9 more than 8 | 20 + 18 | 3 less than 40 |
| 50 - 3 | 54 + 5 | 5 less than 60 | 51 + 6 | 12 + 13 |
| 41 + 5 | 46 – 9 | 38 + 7 | 18 + 18 | 34 minus 7 |
| 26 + 2 | 68 - 11 | 6 more than 23 | 9 + 7 | 13 + 5 |
| 42 + 6 | 12 + 7 | 1 less than 50 | 47 + 9 | 7 more than 32 |
- Example set of questions for board with a 5 by 5 square beginning at 40:
| 20 + 21 | 84 - 1 | 3 more than 40 | 80 - 40 | 3 less than 66 |
| 57 - 3 | 68 + 5 | 80 + 0 | 41 + 1 | Place value of 6 in 68 |
| 59 + 5 | 63 – 9 | 37 + 5 | 25 + 25 | 51 – 7 |
| 71 + 3 | 83 - 11 | 8 more than 74 | 20 + 50 | 10 less than 61 |
| 60 + 2 | 30 + 31 | 85 – 4 | 67 + 4 | 6 less than 90 |