subtracting 3 digit numbers
TRANSCRIPT
WHY DO I REGROUP AND HOW DO I DO
IT?Let’s find out!
WHAT DO YOU DO WHEN THERE ARE NOT ENOUGH ONES TO SUBTRACT FROM?➤ Let’s make a model!
➤ Now, let’s trade a ten!
➤ Why did we need to regroup?
2 27-
WHY DO WE NEED TO REGROUP?
2 27-
We need to regroup because we don’t have enough ones to take away 7.
There are more ones on the floor.
HOW DO WE REGROUP?
2 27-
We need to regroup by borrowing a ten.
Go next door and get 10 more.
1
HOW DO WE REGROUP?
2 27-
We need to regroup by borrowing a ten.
Go next door and get 10 more.
1 12
NOW WE CAN SOLVE THE PROBLEM
2 27-
We need to subtract the ones first.
12-7 is 5 (11, 10, 9, 8, 7)
1 12
5
NOW WE CAN SOLVE THE PROBLEM
2 27-
Now, we subtract the tens.
1-0 is 1
1 12
50
WHAT DO YOU DO WHEN THERE ARE NOT ENOUGH TENS TO SUBTRACT FROM?
➤ Let’s make a model!
➤ Now, let’s trade a hundred!
2 55-
89
0
WHY DO WE NEED TO REGROUP?
8 55-
We need to regroup because we don’t have enough tens to take away 9 tens.
There are more tens on the floor.
29
0
HOW DO WE REGROUP?
8 55-
We need to regroup by taking 1 hundred and give it to the tens.
Go next door and get ten more.
29
0
1
HOW DO WE REGROUP?
8 55-
We need to regroup by taking 1 hundred and give it to the tens.
Go next door and get ten more.
29
0
1 18
NOW WE CAN FINISH SOLVING
8 55-
We already subtracted the ones, so now we subtract the tens.
18-9= 9 because I know 9+9=18.
29
0
1 18
9
NOW WE CAN FINISH SOLVING
8 55-
We already subtracted the tens, so now we subtract the hundreds.
1-0=1, so the answer is 190
29
0
1 18
901