Addition and Subtraction Word Problems
WALT: Use different strategies to solve addition and subtraction word problems
Place Value Partitioning
Problem:
There are 243 worms in the yard. 189 worms can be seen above ground. How many worms are underground?
Solution - Place Value Partitioning:
243 - 189 = ?
200 - 100 = 100
140 - 80 = 60
63 - 9 = 54
Problem:
Peter raised $128 before his fun run and another $54 after the fun run. How much money did Peter raise altogether?
Solution - Place Value Partitioning:
Use the strategy stated to solve each problem
Using this same problem - try using another strategy to solve the problem. See if you come up with the same answer
Reversibility
Problem:
There are 243 worms in the yard. 189 worms can be seen above ground. How many worms are underground?
Solution - Reversibility:
243 - 189 = ?
189 + 1 = 190 + 10 = 200 + 43 = 243 so…
1 + 10 + 43 = 54
2) Reversibility
Problem:
There are 153 birds in a tree. A cat came along and 69 flew away. How many birds are left in the tree?
Solution - Reversibility:
Use the strategy stated to solve each problem
Using this same problem - try using another strategy to solve the problem. See if you come up with the same answer
Rounding and Compensation
Problem:
There are 243 worms in the yard. 189 worms can be seen above ground. How many worms are underground?
Solution - Rounding and Compensation:
243 - 189 = ?
243 - 190 = 53 + 1 = 54
3) Rounding and Compensation
Problem:
Josephine had collected 258 shells along the beach in the morning. By the end of the afternoon she had 296. How many shells did Josephine collect in the afternoon?
Solution - Rounding and Compensation:
Use the strategy stated to solve each problem
Using this same problem - try using another strategy to solve the problem. See if you come up with the same answer
Equal Additions
Problem:
There are 243 worms in the yard. 189 worms can be seen above ground. How many worms are underground?
Solution - Equal Additions:
243 - 189 = ?
244 - 190 = 54
4) Equal Additions
Problem:
Sarah had 345 lollies and shared some with her friends. In the end, she only ended up with 76 lollies left. How many had Sarah given away?
Solution - Equal Additions:
Use the strategy stated to solve each problem
Using this same problem - try using another strategy to solve the problem. See if you come up with the same answer
Subtracting in Parts
Problem:
There are 243 worms in the yard. 189 worms can be seen above ground. How many worms are underground?
Solution - Subtracting in Parts:
243 - 189 = ?
243 - 100 = 143
143 - 80 = 63
63 - 9 = 54
5) Subtracting in Parts
Problem:
There are 4722 people living in GI. 1396 people had to move out due to the housing development. How many people are there still living in GI?
Solution - Subtracting in Parts:
Use the strategy stated to solve each problem
Using this same problem - try using another strategy to solve the problem. See if you come up with the same answer
Extras for Experts (a)
Mrs Ilaoa wants to make 15 litres of juice for the party. Each litre of juice takes ¼ of a sachet of raro. How many sachet’s will Mrs Ilaoa need to make 15 litres?
What about 20 litres?
37 litres?
50 litres?
Extras for Experts (b)
Mrs Ilaoa was making ANZAC biscuits for ANZAC day. Each batch required ¾ a pack of butter. How packs of butter would Mrs Ilaoa require if she baking. Nine batches of biscuits?
What about 15 batches of biscuits?
Extras for Experts (c)
Mrs Ilaoa wants to make 12 litres of PVA glue for the school resource room. Each litre of glue takes 5 of a sachet of flour. How many sachet’s will Mrs Ilaoa need to make 12 litres?
25 litres?
40 litres?