Directions: Using the digits 1 to 9 at most one time each, place a digit in each box to make the smallest (or largest) sum.

### Hint

In the two-digit number, what does the digit on the left represent? What does the digit on the right represent?

### Answer

97 + 86 is one answer for the largest sum. 13 + 24 is the smallest sum.

Source: Robert Kaplinsky

My second grade class loves coming up with variations on this. My personal favorite so far is what is the largest sum you can make with the biggest difference between the two numbers? I also like what is the largest/smallest you can make with only even or odd numbers?

96+87 for largest and 14+23 for smallest . Since you are only moving a “one”, the value of the sum remains the same

40+60=100

97+86

98+76

lasr :13+24=37

high:97+86=183

25+34

98+01

19 + 43

Smallest :13+24=37

highest:97+86=183

12 + 34 =46

98 + 76 = 174

small 38+50 = 88

large 70+ 40 = 110

25 34

97+86

13+24

smallest-15+27

largest-45+36

16+82=98

12+36=48

no repeating numbers and all numbers are less than 9

75+43

Largest 97+86

Smallest 13+24

LARGE 87+96

SMALL 1+2

97+86