Page 22 - TG_G1_CH6_CHRIS

Counting Tens
• Cut the number cards from the Workmat. Have children cut the number cards from the Workmat and put them in the
• Paste the number cards to fill in the missing number on each number line.
top of the page.
Say: Counting on tens after 46, what is the number between 86 and 106? 96
46 56 66 76 86 96 106 Paste it on the number line. Counting on tens after 23, what is the number
between 33 and 53? 43 Paste it on the number line. Counting back tens from
85, what is the number between 25 and 5? 15 Paste it on the number line.

23 33 43 53 63 73 83
ANCHOR ACTIVITY

85 75 65 55 45 35 25 15 5 Use the Anchor Activity for this lesson as a warm-up to gauge
children’s prior knowledge and help them engage at the
beginning of class.

1.NBT.5 Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count, explain the reasoning used.
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TIME TO LEARN
TIME TO LEARN

You can use the number line to jump forward 10
and jump back 10.
Recall the meaning of counting on and counting back. Provide each child
with an empty number line. Say: Count on 10, starting with 0, until you reach
0 10 20 30 40 50 60 70 80 90 100 110 120
5 15 25 35 45 55 65 75 85 95 105 115
reach 120. Record your counting on the number line.
65, 75, 85, 95, 105, 115 counting on 10 Discuss with children the possibility of using a number line to count forward or
65, 55, 45, 35, 25, 15, 5 counting back 10 backward in 10s. Draw their attention to counting in 10s. Only the tens place
changes; the ones place usually remains the same.
0 10 20 (pause) 10 0
STEP count on 10
BY
STEP A. Write the missing numbers. count back 10 Have children use their number lines to complete the following:
,
,
65 , ___ , ___, ___ , ___ , 115
1 33, 43, 53 63 73
85 95 105
75
2 107, 97, 87 , 77 , 67
25
35
55
5 , ___ , ___ , ___ , ___ , ___ , 65
15
45
B. Count on 10.
1 40 50 60 70 80 90 100 2 60 70 80 90 100 110 120
43 53 63 73 83 93 61 71 81 91 101 111
C. Count back 10.
1 60 70 80 90 100 110 120 2 30 40 50 60 70 80 90
Common
68 78 88 98 108 118 39 49 59 69 79 89 Common
Errors
Errors
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Children count easily on or back with numbers that end with 0 or 5.
Other numbers might be more difficult.

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