Page 227 - NUMINO TG_4A

15Unit Whose Equation Is Correct?

jOb ective Write equations dividing a two-digit number by a one-digit number.

1. Textbook Instructions q

UNIT

15 Whose Equation Is Correct?

Students will learn how to divide a 2-digit Thomas and Ryan used each of the number cards once to make the
number by a 2-digit number and a 3-digit division sentence.
number by a 2-digit number.
r r
First, have the students revise by dividing a 2-
digit number by a 1-digit number. )Ω )Ω
Thomas and Ryan used 3, 3, 4, and 15 to
make two division sentences. Chat
Find who made the correct division
sentence. How can this be found? Who made the correct division sentence? Discuss why the other
Divide 15 3 and 15 4. Compare your results division sentence is wrong.
with Thomas’ and Ryan’s.
Ryan made the correct division sentence.
Have the students calculate both division Thomas’ division sentence, 15 divided by 3, equals 5.
problems, and then find who wrote the
correct division sentence.
Then, have them discuss why the other
division sentence is incorrect.
Thomas: 15 3 5
Ryan: 15 4 3 r3
Ryan has the correct division sentence
and quotient.
Thomas incorrectly solved his problem.
Thomas’ quotient should be 5.

124

2. Build Understanding 2
3 89
Have the students revise how to divide a 2-digit number by a 1-digit number.
Example: 89 3 60
2
Divide the tens place. Multiply, subtract, and compare.
There are two tens in each group. Put 2 in the quotient over the tens place.
Multiply. 3 2 6
Subtract. 8 6 2
Compare. 2 3

210 NUMINO Teacher s Guide