Page 48 - TG_G1_CH6_CHRIS

I counted 42 birds in a tree. My
1 I counted 42 birds in a tree. My Problem-Solving questions 1 and 2 include:
friend John counted 9 more
friend John counted 9 more
birds. How many birds did we
birds. How many birds did we • Adding 2-Digit numbers with regrouping
see altogether?? • Solving word problem concerning Addition of 2-Digit number with
see altogether
51 birds regrouping
birds
Anthony made a number
2 Anthony made a number
sentence with 3 number
sentence with 3 number This is his number sentence. In order to reinforce children’s ability to add 2-digit numbers with regrouping in
This is his number sentence.
cards and 2 symbol cards. a real-life situation, have them solve problem 1. Encourage them to read the
cards and 2 symbol cards.
63
=
Does his number sentence
Does his number sentence 5 5 6 6 + + 7 7 = 63 situation carefully and guide them to use the place value chart to add with
add up to the greatest sum??
add up to the sum
Is he correct regrouping to find the sum of birds in the tree. The answer is 51 birds.
Is he correct? Explain.? Explain.
Yes. 7+6 is 1 ten and 3 ones. Add the 10 to
6 5 7 7 + + = = Then have children explore a situation that includes making an inference and
6 5
justifying the answer in their own words in problem 2. Encourage children to
the 5 tens in 50. Then keep the 3 ones.
read the problem carefully. Guide them to use addition with regrouping in
Match.
Vocabulary Check Match. order to check Anthony’s answer is correct. Let them make their own clue to
find the sum using the given number cards. Yes, the sum comes when adding
adding with regrouping 36 + 5 = 41 76 + 5 = 81.
adding with regrouping
36 + 5 = 41
36 + 3 = 39
adding without regrouping
adding without regrouping 36 + 3 = 39
After solving exercises 1 and 2, copy the additional problems below onto the
board for group or individual work. The additional problems are based on
adding 2-digit numbers with regrouping. In problems 1 and 2, ask: How do
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you add numbers with regrouping? Encourage children to use addition with
regrouping to find each sum.
Vocabulary Check
If children have difficulty, give them a place value chart and some counters
If children struggle to make the matches, and guide them to add with regrouping using the counters to solve the
review adding with regrouping in the Practice problems.
exercises.
Additional problem 1
Youssef counted the number of street lamps on his way back home. He found
25 lamps. The next day there were 18 more. How many lamps are there in all?
We can use the place value chart to add two 2-digit numbers with regrouping.
EXIT ACTIVITY There are 43 lamps in all.
Additional problem 2
Use the Exit Activity for this lesson to In a shop there were 57 toy cars. Two children each bought 15 cars. How many
reinforce children’s understanding. This toy cars are left in the store?
can be used as an informal formative 27 cars
assessment.
CLOSURE

At the end of the lesson, make sure children understand the main concept of the lesson by asking them explain how to solve
15 + 16.
Tens Ones
Children can use the place value chart to add two 2-digit numbers.
We add ones to ones; if they make 10, we write the ones and we add ones to tens. 1+1 5
The place value chart shows the answer. + 1 6
3 1

439
439