Division by One Digit Divisors Allegra James and

Division by One Digit Divisors Allegra James and Larry Wershbale Media Design and Production ISTC 665

What are you doing when you divide? • When you divide, you are trying to split something into equally numbered groups • Dividing these 16 apples into 4 equal groups, gives you 4 groups that have 4 apples in each of the groups: • Take these 16 apples:

Division by One-digit Divisors • Today you will learn how to divide a three-digit dividend by a one-digit divisor, to get a quotient without a remainder • Let’s review these terms

What are the parts of a division problem? • • The dividend is the number you are dividing The divisor is the number you are dividing by The quotient is the evenly divided result The remainder is what is left over that cannot be evenly divided

When we write the problem like this: 136 5 = 27 r 1 136 is the dividend 5 is the divisor 27 1 is the quotient remainder

When writing it like this: 5, the divisor, moves to here 27 r 1 1 is the remainder 5 136 27, the 136, the quotient, stays dividend, here moves here

How do you solve a division problem? • Solving a division problem is a step by step process • The method we will learn today is based the words for the people in our families. • They are: Dad Mom Sister Brother

The “Family” Method Dad = Divide Mom = Multiply Sister = Subtract Brother = Bring Down

Dad • Dad stands for divide • Start by looking at the first number in the dividend • Divide the first number by the divisor by finding a multiple that comes closest to that number, without going higher, then write the other factor above the 1 st number. • Use your knowledge of math facts, or a multiplication grid

Dad = divide by the number closet to the first digit, (find it on your grid) 3 2 711 • In the 3’s, the number closest to 7, but not more than 7, is 6 • The other factor is 2 • Put a 2 above the 7 2 6

Mom = multiply the new quotient times the divisor • You found 2, multiply it times the divisor, 3 • 2 times 3 equals 6 2 X 3=6 • Put a 6 under the 7 3 2 711 6

Sister = subtract the number you got by multiplying the divisor, from the number in the dividend • You got a 6 when you multiplied • Subtract 6 from 7 • 7– 6=1 2 3 711 – 6 1 • The difference must be smaller than the divisor!!!

Brother = bring down the next number, from the number in the dividend • Bring down the next number in the dividend • The new number you have is 11 2 1 3 711 – 6 11 • Now start over again with Dad for the tens

Now, let’s do the second step • Dad: 9 is the closest multiple, the other factor you found is 3 • Mom: 3 X 3 = 9, put a 9 under the 11 • Sister: subtract 9 from 11 11 - 9 = 2 • Brother: bring down the 1 23 1 3 711 – 6 11 – 9 21

Now, let’s do the last step • • 2 37 Dad: 21 is the closest multiple, 1 3 711 the other factor is 7 – 6 Mom: 7 X 3 = 21, put 21 under 11 the 21 – 9 Sister: subtract 21 from 21 21 21 - 21 = 0 – 21 Brother: nothing’s left, you’re done! 0

Now, let’s practice! • Dad • Mom • Sister • Brother 2 6 864 4 8 – 8 06

Now, let’s do the second step • Dad • Mom • Sister • Brother 21 64 4 864 – 8 06 – 4 24

Now, let’s do the last step • Dad • Mom • Sister • Brother 2 16 6 4 864 – 8 06 – 4 24 – 24 0

What do I do with division now? • Finish the rest of the worksheet • Homework: probs. 1 -10, p. 64 in text • Go to this icon on the class’ computers for extra practice if you have free time • Look for the same icon on the class’ website for practice at home