Strategy Practice
Write 153 – 24 in vertical form.
153
– 24
_______
Milan had 143 books. Aria gave him 36 more. How many grapefruits does Milan have now?
Milan has 179 grape fruits now.
44 + 38 = ___
82
173
+ 51
______
In what place do you begin solving the problem?
The one's place!
83 − 31 = ___
52
Solve 222 + 218 by making a friendly ten.
(Step 1) 222 + 218 = 222 + (8 + 210)
(Step 2) (222 + 8) + 210 = 230 + 210
(Step 3) 230 + 210 = 240
Calum had 259 stamps. He gave 143 of them to JJ. How many stamps does Calum have left?
Calum has 116 stamps.
367 + 24 = ___
391
What is the rule for adding a 0 to any number?
92 − 45 = ___
47
Solve 152 - 138 using addition.
(Step 1) 138 + 2 = 140
(Step 2) 140 + 12 = 152
(Step 3) 2 + 12 = 14
(Step 4) 152 - 138 = 14
Ms. Ells has 318 big stickers and 253 small stickers. How many stickers does Ms. Ells have in all?
Ms. Ells has 571 stickers in all.
275 + 153 = ___
428
What do you do when there is "more on the floor" when you are subtracting?
Go next door and take 10 more!
257 − 64 = ___
193
Solve 476 + 219 using expanded form.
476 = 400 + 70 + 6
219 = 200 + 10 + 9
400 + 200 = 600
70 + 10 = 80
6 + 9 = 15
600 + 80 + 15 = 695
Clark University has 649 students graduating and Worcester State has 547 students graduating. How many more students are graduating at Clark University than at Worcester State?
Clark University has 102 more students graduating than Worcester State.
825 + 97 = ___
922
What strategy is being used below?
157 + 233 = 157 + (3 + 230) =
(157 + 3) + 230 = 160 + 230 = 390
Making a friendly ten!
900 − 478 = ___
422
Solve 1000 – 853 using regrouping.
147
(Ms. Ells will show how to do it)
There are 827 whales and 1219 sharks in the Atlantic Ocean. How many fewer whales are there than sharks?
There are 392 fewer whales than sharks.
549 + 576 = ___
1125
What does regrouping mean? How do you regroup?
Regrouping changes 10 ones into 1 ten (addition), or 1 ten into 10 ones (subtraction).
Regrouping can also change 10 tens into 1 hundred (addition), or 1 hundred into 10 tens (subtraction).
It organizes numbers that are too big for one column (place value), making large addition and subtraction problems simpler.
1340 − 298 = ___
1042