Adding & Subtracting Three-digit Numbers

Mathematics, Grade 3

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Adding Three-digit Numbers Subtracting Three-digit Numbers Add the ones: Regroup: What is the total number of marbles? How many more marbles does Sue have than Mike? A B Ungroup: B 7 ones + 8 ones = 15 ones Subtract the ones: A 1 ten = 10 ones Ungroup: B Subtract the tens: A 1 hundred = 10 tens Subtract the hundreds: A 16 ones 8 ones = 12 tens 4 tens = Add the tens: A 1 ten + 4 tens + 7 tens = 12 tens Add the hundreds: A 1 hundred + 1 hundred + 2 hundreds = 4 hundreds 15 ones = Regroup: B 12 tens = Step 1 Step 2 Step 3 Step 1 Step 2 Step 3 1 4 1 7 2 + 5 ones tens hundr eds 1 1 1 2 + 7 8 5 2 ones tens hundr eds 1 4 7 + 7 8 5 ones tens hundr eds 2 4 425 total number of marbles 1 2 16 3 4 4 2 8 ones tens hundr eds x xx x xx xx xx 3 16 4 2 6 8 8 ones tens hundr eds 12 2 16 3 4 6 8 8 8 1 ones tens hundr eds 12 278 Sue’s marbles 147 Mike’s marbles 7 8 4 7 1 2 6 8 2 3 4 8 xx hundreds hundreds = 3 2 16 ones 8 ones = 8 ones 12 tens 4 tens = 8 tens hundreds hundreds = hundred 3 2 1 3 4 2 © Copyright NewPath Learning. All Rights Reserved. 93-4301 www.newpathlearning.com Adding & Subtracting Three-digit Numbers 248 436 Mike’s marbles Sue’s marbles
Adding Three-digit Numbers Subtracting Three-digit Numbers Add the ones: Regroup: What is the total number of marbles? How many more marbles does Sue have than Mike? A B Ungroup: B 7 ones + 8 ones = 15 ones Subtract the ones: A 1 ten = 10 ones Ungroup: B Subtract the tens: A 1 hundred = 10 tens Subtract the hundreds: A 16 ones 8 ones = 8 ones 12 tens 4 tens = 8 tens Add the tens: A 1 ten + 4 tens + 7 tens = 12 tens Add the hundreds: A 1 hundred + 1 hundred + 2 hundreds = 4 hundreds 15 ones = 1 ten and 5 ones Regroup: B 12 tens = 1 hundred and 2 tens Step 1 Step 2 Step 3 Step 1 Step 2 Step 3 4 1 7 2 + ones tens hundr eds 1 2 + 7 8 5 2 ones tens hundr eds 4 7 + 7 8 ones tens hundr eds 425 total number of marbles 2 16 3 4 4 2 8 ones tens hundr eds x xx x xx xx xx 3 16 4 2 6 8 8 ones tens hundr eds 2 16 3 4 6 8 ones tens hundr eds 278 Sue’s marbles 147 Mike’s marbles 7 8 4 7 1 2 6 8 2 3 4 8 xx hundreds hundreds = hundred 3 2 1 3 4 2 Key Vocabulary Terms add ones total digit regroup ungroup hundreds subtract more tens © Copyright NewPath Learning. All Rights Reserved. 93-4301 www.newpathlearning.com Adding & Subtracting Three-digit Numbers 248 Mike’s marbles 436 Sue’s marbles \|xiBAHBDy01633lz[