Mathematics
Having fun with pocket calculators and negative numbers
Educator section
Memorandum
23. a) -7 m
- -20 m
- -16 m
- -15 m
25. 22nd floor
Leaner section
Content
Activity: having fun with pocket calculators and negative numbers
23. Some friends decided to go bungee jumping. Calculate how far below the bridge each one turned.
a) __________________________________________________________________
b) __________________________________________________________________
c) __________________________________________________________________
d) __________________________________________________________________
24. LET’S PLAY A GAME!!
Work with a friend. Remove the Jack, Queen, King, Ace and Joker from a deck of playing cards. Place the rest of the cards face down between the two of you. Take number 10 as a starting point.
Player 1: Pick up a card. If it is a black card, add the total / the number on the card to 10, but subtract the number if the card is red.
Player 2: Pick up a card. Do the same as player 1.
The players must check each other’s answers. Use a pocket calculator if you are unsure. Continue playing until the totals / numbers on all the cards have been added or subtracted.
25. BRAIN TEASER!
You are in a lift on the 4 th floor of a building with basement floors. You come down 6 floors, then go up 13 floors and then come down 11 floors. Then you come down 9 floors and go up 23. You come down 17 floors again and go up 25. At which floor will you get out? ________________ . Show this in a sketch or on a number line.
26. CHALLENGE!
Draw a time line on which you indicate important events that occurred before as well as after your birth. Indicate your birth year as 0.
27. SELF-ASSESSMENT
Tick in the appropriate block:
| I can | GOOD | BETTER | BEST |
| provide examples of negative numbers from everyday life. | __________ | __________ | __________ |
| key in negative numbers correctly into my pocket calculator. | __________ | __________ | __________ |
| arrange negative numbers from smallest to largest and vice versa. | __________ | __________ | __________ |
| add and subtract negative numbers with the help of my pocket calculator. | __________ | __________ | __________ |
| complete flow diagrams with negative numbers correctly. | __________ | __________ | __________ |
| do calculations involving negative numbers without a pocket calculator. | __________ | __________ | __________ |