-10 or -100
298 - 100 = ?
198
How would you decompose 356?
300 + 50 + 6
Which side of an open number line do you start on when subtracting?
The right side.
Johnny has 246 markers. He gives 100 to Ruby. How many markers does he have left?
246 - 100 = 146
What strategies did we use to subtract 3-digit numbers?
Place Value Chart
Decomposing
Adjusting Numbers
Number Line
574 - 10 = ?
564
How many tens are in 276?
7 tens = 70
Should you jump your hundreds, tens, or ones first?
Your hundreds.
Josie has 456 pencils. She gives 10 to Charlie. How many pencils does she have left?
446
If I need more tens, what do I need to regroup to get more?
Hundreds
Turn one hundred into ten tens.
908 - 100 = ?
808
Her Work:
500 + 2 + 7
No.
It should have been :
500 + 20 + 7
Solve using a number line:
526 - 105 = ?
421
Max played Fortnite for 274 hours. Josh played for 124 hours. How many more hours did Max play for?
273 - 124 = 150 hours more
If I subtract 500 - 276, where will I need to regroup?
You will need to regroup the hundreds into tens AND the tens into ones.
307 - 10 = ?
297
Their Work:
300 + 90 + 0
No. 300 + 90 + 0 = 390
The correct way to decompose this number is:
300 + 0 + 9
Kit solved 573 - 122 on a number line.
He hopped back 100, and landed on 473. Then he hopped back 20 and landed on 443. Then he went back 2 and got the answer of 441. Kit is wrong. Where did he go wrong?
He went back 30, instead of 20.
Bayley ran for 767 seconds. Daisy ran for 349 seconds. How many more seconds did Bayley run for?
767 - 349 = 418 seconds more.
Why do we start on the right side of the number line when subtracting?
You need to count BACK and if you started on the left side, you couldn't go backwards.
507 - 110 = ?
397
Who decomposed 578 correctly:
Joan: 500 + 70 + 8
Jenn: 500 + 50 + 28
BOTH.
Use a number line to solve.
541 - 296 =?
245
Mark has 346 stickers. He got some more stickers from his friend. Now he has 588 stickers. How many more did he get from his friend?
346 + ? = 588
588 - 346 = 242 stickers
Barbie has 542 pairs of shoes. She gives 100 to Skipper. Then, her friend Weird Barbie gives her 120 more. How many pairs of shoes does she have now?
562 pairs of shoes.