Level 1 students began the year using numbers through 10, but now it’s time to extend their learning to interpreting and using numbers through 99. Two-digit numbers are everywhere, and most children have seen and used them to tell ages of older people, determine how many children are in the class, read the calendar, and find prices under $1.00. This unit includes practice in reading and writing numbers, comparing and ordering them, and using ordinal numbers. Skipcounting by 2’s, 5’s, and 10’s lets children count quickly, read time in five-minute intervals, count nickels and dimes, and assimilate important guide numbers for counting with greater numbers.
The unit also features work with some interesting and valuable problem solving strategies— using pictures and finding patterns. Applying their understanding of what 10 objects look like and what place value means, children estimate greater numbers of objects and then find groups of 10 to verify their answers.
This unit is built around place-value concepts.
The place-value system groups numbers, therefore making it possible to write very great numbers with relatively few digits. The place-value system is also additive; we add the values in each place for a total value. Thus Level 1 students learn that a number like 35 means 3 tens and 5 ones, or
30 and 5, or 30 ⫹ 5.
A Positive Start
Place value lays the foundation for future work with greater numbers and also for understanding decimals. Children need to picture numbers and understand their values rather than simply learning them by rote. The ideas and models you develop for this unit may serve you your entire teaching career. Collect images, prepare number lines and hundreds charts on poster board, and enlist the creative ideas of other teachers.
Not only will you help children achieve this year’s goals, but by looking ahead, you can prepare them well for the next level. Use the chart to see what children learned last year and what they’ll learn in Level 2.
Concept/Skills
Identifying Tens and Ones
Last Year
Identify tens and more in numbers to 30
This Year
Identify tens and ones in numbers to 99
Next Year
Identify hundreds, tens, and ones in numbers to 1000
Counting,
Comparing, and
Writing Numbers
Count, write, and compare numbers to 30
Count, compare, and write numbers through 99
Order, compare, and write numbers through 1000
Use the Find a
Pattern Strategy to Solve
Problems
Identify the next number in a repeating number pattern
Identify 1 more than and 1 less than a given number and 10 more and 10 less than a number on a hundred chart
T100 Unit 7
Identify the next most likely number in number patterns

Gather numerous objects for counting and work with children to see what numbers such as 34 and 79 look like. Plan different ways for children to handle the materials and relate them to place-value charts, number lines, and hundred charts.
Begin by writing the numbers 1 through 10 and asking children what’s special about 10. Point out that it has two digits and sets a pattern for other two-digit numbers. Have children handle groups of 12 and 16 counters, gathering 10 in a group, and then seeing 1 group and 2 counters; 1 group and 6 counters.
• Explain that each “teen” number means 10 and another number less than
10.
Fifteen means 10 and 5. Lead children in saying number words for 10 through 19 and then writing them.
• Provide counters and show children how to count and group or bundle counters when they reach 10 or a multiple of ten.
Ask: Can you make a group of 10 yet? No? Let’s keep counting: 17, 18, 19, 20.
Can you make a group of 10 now?
Have children make another group, then write 20 and discuss the idea that
20 means 2 groups of 10 and 0 ones.
Show This:
Tens Ones
Visual Aids Use these simple visual organizers and have children show 15, 11, and 18 with counters, 10 on the frame and the rest to the side. Ask children to tell the number of tens and ones for each number.
Help from Home Ask family members to participate by giving them specific tasks. For example, suggest that they work with the children to make a chart that shows the place values of numbers from 11 through 19, including visual examples and the words clearly printed. Charts can be used in class or kept at home for math support.
More Materials Work with each child to make a tens and ones workmat out of paper folded once and then labeled on each side of the fold. Use bundled and loose straws or craft sticks to represent tens and ones.
Demonstrate the number with counters.
Vocabulary Development Develop the meaning of tens and ones with models and pictures. Help children build the habit of displaying tens to the left and ones to the right, as numbers are written and read.
Common Misconceptions It’s easy to see why children confuse numbers like 58 and 85; they have the same digits. Models, place-value charts, and explanations show them how different the numbers are, that the order of the digits is crucial.
Learning greater numbers is exciting, and some children like to “go wild” with numbers, expressing their enthusiasm. When you solicit examples, give a range so that children don’t jump too far ahead.
• Use two-digit number cards. Choose one and have children read it, then count on from that number.
• Introduce number lines for a series of numbers, such as 10–20, 30–50, and
60–90. Use adding machine tape to make a number line to stretch across the room. Write multiples of 10 in one color, and write 5 and numbers ending in 5 in another. Have children locate numbers, tell if the numbers are greater or less than a given number, and tell their place values.
Teaching Strategies T101