Unit 3: FUN WITH MODELS (ADDING AND SUBTRACTING)
Examples:
1. James has 93 postcards. Anya has 62 postcards. How many postcards do they have altogether?
James has postcards = 93
Anya has postcards = 62
∴ They have postcards altogether = 93 + 62 = 155
Answer: They have 155 postcards altogether.
2. Aunt Lily had $59. She spent $17 on a book. How much did she have left?
Aunt Lily had = $59
She spent = $17
∴ she had left = $59 – $17 = $42
Answer: She had $42 left.
Draw the models, and solve the following story problems.
1. Danny has 576 bookmarks. Emilio has 186 bookmarks. How many bookmarks do they have altogether?
They have ________ bookmarks altogether.
Solution1:
Danny has bookmarks = 576
Emilio has bookmarks = 186
∴ They have bookmarks altogether = 576+186 = 762
Answer: They have 762 bookmarks altogether.
2. Eddy has 280 chickens. He sells 168 chickens. How many chickens does he have left?
He has ______ chickens left.
Solution2:
Eddy has chickens = 280
∴ He sells chickens = 168
He has chickens left = 280-168 = 112
Answer: He has 112 chickens left.
3. A shopkeeper sold 360 apples on Monday. He sold 275 apples on Tuesday and another 150 apples on Wednesday. How many apples did he sell altogether?
He sold _______ apples altogether.
Solution:
A shopkeeper sold apples on Monday = 360
sold apples on Tuesday = 275
sold apples on Wednesday = 150
∴ He sold apples altogether = 360 + 275 + 150 = 785
Answer: He sold 785 apples altogether.
4. Samantha had 96 seashells. She gave some to her best friend. She had 78 seashells left. How many did she give to her best friend?
She gave _______ seashells to her best friend.
Solution:
Samantha had seashells = 96
She had seashells left = 78
∴ She gave seashells to her best friend = 96 – 78 = 18
Answer: She gave 18 seashells to her best friend.
5. Andy received 131 stamps from his father. His sister gave him 280 stamps. How many stamps did he have altogether?
He had _______ stamps altogether.
Solution5:
Andy received stamps = 131
His sister gave stamps= 280
∴ He had stamps altogether = 131+280 = 411
Answer: He had 411 stamps altogether.
6. There are 216 chickens (🐓), 137 ducks (🦆), and 97 rabbits (🐇) on a farm. How many animals (chickens+ducks+rabbits) are there on the farm?
There are _____ animals on the farm.
Solution6:
There are chickens = 216
ducks = 137
rabbits = 97
∴ Animals on the farm = 216+137+97 = 450
Answer: There are 450 animals on the farm.
7. Malik had 720 trading cards. He gave some to his brother. He had 465 trading cards left. How many trading cards (🃣) did he-give-to his brother?
He gave ____ trading cards to his brother.
Solution7:
Malik had trading cards = 720
He had trading cards left = 465
∴ He give-to his brother = 720 – 465 = 255
He gave 255 trading cards to his brother.
8. Hitomi saves $310. Her brother saves $280 more than Hitomi.
(a) How much does her brother save?
Her brother saves $______
Solution:
Hitomi saves = $310
∴ Her brother saves = $310 + $280 = $590
Answer: Her brother saves $590.
(b) How much do they save altogether?
They save $ _______ altogether.
Solution:
Hitomi saves = $310
Her brother saves = $590
∴ They save altogether = $310 + $590 = $900
Answer: They save $900 altogether.
