Page 67 - NUMINO TG_4A

04Unit Numbers in Disguise

jOb ective Make addition and subtraction sentences with 4-digit numbers.

1. Textbook Instructions UNIT

Students will solve problems involving the 04 Numbers in Disguise
addition and subtraction of whole numbers.
First have the students use the digits from 1 to Use number cards from 1 to 8 once to make an addition sentence with
8 to make an addition sentence that has the the greatest sum and a subtraction sentence with the least difference.
greatest sum and a subtraction sentence that
has the least difference. The Greatest Sum
Use the digits from 1 to 8 to add 4-digit
numbers to make the greatest sum. 86 42
In order to make the greatest sum, the 75 31
thousands digits must be the greatest and 1 6,1 7 3
the ones digits must be the least. What
digits must go in the thousands places? The Least Dif ference
7 and 8.
What digits must go in the hundreds 51 23
places? 48 76
6 and 5.
What digits must go in the tens places? 2 47
4 and 3.
What digits must go in the ones places? 30
2 and 1.
The greatest sum can be made by adding:
(8,000 7,000) (600 500) (40 30)
(1 2) 16,173
Now subtract 4-digit numbers to make the
least difference.

Refer to .

2. Build Understanding

The Least Difference

In order to make the least difference, the two numbers must be as close as possible. Solve using the
following method.

Step 1. Have the letters from A-H represent each digit. Place the digits so that the difference between FGH
and BCD will be the greatest. FGH must be the greatest number and BCD must be the smallest
number that can be made. FGH 876, BCD 123.

ABCD F GH 876
E FGH BCD 123

050 NUMINO Teacher s Guide