2 Digit and 1 Digit Numbers
24 + 3
27
Start at 32 on a hundred chart. Move 2 tens. What number do you land on?
52
Start at 25 on an open number line. Make one jump of +10. Where do you land?
35
Break apart 27 into tens and ones.
20 + 7
Is 16 even or odd? Explain how you know.
Even
35 + 7
42
Start at 24. Move 3 tens and then 5 ones. Where do you land?
59
Solve 32 + 24 using an open number line. Start at 32, jump +20, and then jump +4. What is the sum?
56
Solve 25 + 15 by breaking apart 15 into tens and ones.
25 + 10 =35 35; 35 + 5 = 40
Is 23 even or odd? Explain how you know.
Odd; one object will be left without a partner when making pairs.
46 + 8
54
Use a hundred chart to solve 34 + 23. What is the sum?
57
Solve 45 + 32 using an open number line. What jumps could you make?
+30 and +2; sum = 77
Solve 35 + 24 by breaking apart 24 into tens and ones.
35 + 20 = 55; 55 + 4 = 59
An array has 4 rows with 5 counters in each row. How many counters are there altogether? Is the total even or odd?
20 counters; even
Word Problem: Maya has 27 stickers. Her teacher gives her 8 more stickers. How many stickers does Maya have altogether?
35 stickers
Use a hundred chart to solve 46 + 34. What is the sum?
80
Start at 28. Make a jump of +40 and then a jump of +7. What addition problem did you solve, and what is the sum?
28 + 47 = 75
Solve 46 + 37 by breaking apart 37.
46 + 30 = 76; 76 + 7 = 83
Word Problem: A teacher has 24 pencils. She wants to arrange them into 4 equal rows. How many pencils will be in each row? Draw or describe the array. Is 24 even or odd?
6 pencils in each row; 24 is even.
Word Problem: There are 38 students’ books on a shelf. The teacher adds 7 more books. Then she adds 6 more books. How many books are on the shelf now?
51 books
Word Problem: Jordan has 35 baseball cards. His friend gives him 27 more cards. Use a hundred chart to find how many cards Jordan has altogether. Explain how you moved on the chart.
62 cards.
Word Problem: A library has 46 books about animals and 38 books about space. Use an open number line to find the total number of books. Show the jumps you would make.
84 books; one strategy is 46 + 30 = 76, then +8 = 84
Word Problem: A second-grade class collects 28 cans on Monday and 36 cans on Tuesday. Use the break-apart strategy to find the total number of cans collected. Explain your steps.
64 cans; 28 + 30 = 58, then 58 + 6 = 64
Word Problem: There are 5 tables in a classroom. Each table has 6 students sitting around it. Draw an array to represent the groups of students. How many students are there altogether? Is the total even or odd? Explain how you know.
30 students; even