MATH - Grade 2

Math Challenges

Source: https://www.openmiddle.com/category/grade-2/

Activity 1

Directions: Complete the story problem and answer statement.

Version 1 (Difficult)
Lucy has _____ apples. She has nine _____ (more/less) than Marcus. How many apples does _____ (Lucy/Marcus) have?

_____ (Lucy/Marcus) has _____ apples.

Version 2 (Medium Difficulty)
Lucy has _____ apples. She has nine less than Marcus. How many apples does _____ (Lucy/Marcus) have?

_____ (Lucy/Marcus) has _____ apples.

Version 3 (Easy)
Lucy has _____ apples. She has nine more than Marcus. How many apples does Marcus have?
Marcus has _____ apples.

Hint:

Who has more in your problem, Lucy or Marcus?

Should you adjust how many apples Lucy has in the beginning?

How many apples does it make sense for Lucy to have in a “more” problem?

How many apples does it make sense for Lucy to have in a “less” problem?

Challenge: Complete the statement using only numbers within 20.

Multiple Correct Answers:

Lucy has 11 apples. She has nine more (more/less) than Marcus. How many apples does Marcus (Lucy/Marcus) have?

Marcus (Lucy/Marcus) has 2 apples.

Lucy has 12 apples. She has nine less (more/less) than Marcus. How many apples does Marcus (Lucy/Marcus) have?
Marcus (Lucy/Marcus) has 21 apples.

Activity 2

Adding and Subtracting Two-Digit Whole Numbers

Directions: Use the digits 0 to 9, at most one time each, to make a true statement.

Hint:

What’s your best first move? Does it make more sense to start with the addition or subtraction? What’s the greatest value you can find? smallest value?

There are multiple answers including:

24+35=78-19

13+56=97-28

47+36=98-15

Activity 3

Subtraction with Regrouping 2

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to make the difference equal to 39.

Hint: What must be true in order to get a 9 in the one’s place of your difference?

Answer: 52-13, 53-14, 56-17, 63-24, 64-25, 67-28, 68-29, 71-32, 74-35, 75-36, 78-39, 81-42, 82-43, 85-46, 86-47, 87-48, 91-52, 92-53, 93-54, 96-57, 97-58, 98-59

Activity 4

Create an Equation

Directions: Use only the digits 1 to 7, at most one time each, fill in the boxes to create a true statement.

Hint: What place value would you like to start with? What digits “go” together?

Answer: See below

Answer:

Number of Unique Solutions: 20 (40 with commutative property)

1: 43 = 16 + 27

2: 43 = 17 + 26

3: 47 = 32 + 15

4: 47 = 35 + 12

5: 57 = 21 + 36

6: 57 = 31 + 26

7: 61 = 34 + 27

8: 61 = 37 + 24

9: 62 = 15 + 47

10: 62 = 45 + 17

11: 67 = 14 + 53

12: 67 = 54 + 13

13: 71 = 25 + 46

14: 71 = 26 + 45

15: 74 = 23 + 51

16: 74 = 53 + 21

17: 75 = 12 + 63

18: 75 = 13 + 62

19: 76 = 41 + 35

20: 76 = 45 + 31

Activity 5

Sum to 1,000 – Two Addends

Directions: Arrange the digits 1-6 into two 3-digit whole numbers. Make the sum as close to 1000 as possible.

Hint: Which digits will be the most helpful to focus on to make the solution as close to 1,000 as possible?

Answer: 993 (multiple ways to create the solution)

Activity 6

Close to 1000

Directions: Using the digits 1 to 9 exactly one time each, place a digit in each box to make the sum as close to 1000 as possible.

Hint: How do you know you can’t get any closer to 1000? What should be true about the hundreds places of your three numbers? How do the tens places affect your answer?

Answer: Lots of answers will get you 999. One would be 247 + 563 + 189.

Is exactly 1000 even possible? Here’s a Geogebra tool you can use to check your answer.

Activity 7

Sums to 100

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to create the closest possible sum to 100.

Hint: Can you give me 3 numbers that add up to 100 (any number could be repeated)? How can we use this to fill in the boxes using each digit only once?

Answer: Multiple solutions

59+24+17

Activity 8

Subtraction without Regrouping

Directions: Using the digits 1 to 9, at most one time each, fill in the boxes so that you would not need to regroup when you subtract. Make sure your number is less than 63.

Hint: What is a number you can take away from 3?

Answer: The student puts in a number less than 63 and contains a 0, 1, 2, or 3 in the ones place.

Activity 9

Adding Two-Digit Numbers

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.

Activity 10

Subtracting Two-Digit Numbers

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to make the smallest (or largest) difference.

Hint: What does the number on the left represent? What does the number on the right represent?

Answer: 98 – 12 is the largest difference. There are several answers for the smallest difference including 81-79.