Question

b150a kumon
subtraction of 2-digit numbers 3

subtract.
(1) \

$$\begin{array}{r} 63 \\\\ - 20 \\end{array}$$

(5) \

$$\begin{array}{r} 72 \\\\ - 33 \\end{array}$$

(2) \

$$\begin{array}{r} 63 \\\\ - 25 \\end{array}$$

(6) \

$$\begin{array}{r} 72 \\\\ - 51 \\end{array}$$

(3) \

$$\begin{array}{r} 63 \\\\ - 48 \\end{array}$$

(7) \

$$\begin{array}{r} 72 \\\\ - 57 \\end{array}$$

(4) \

$$\begin{array}{r} 63 \\\\ - 36 \\end{array}$$

(8) \

$$\begin{array}{r} 72 \\\\ - 64 \\end{array}$$

Explanation:

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"question_count": 18,
"skills_matched": [
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"table_formatter",
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"quick"
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"concepts_used": [],
"new_concepts": [
"Column Subtraction",
"Subtraction with Regrouping"
],
"current_concepts": [
"Column Subtraction",
"Subtraction with Regrouping"
]
}
</pre_analysis>

<reasoning>

Calculate B149b column subtractions

\[

$$\begin{aligned} (9)\quad &92 - 47 = 45 \\ (10)\quad &92 - 44 = 48 \\ (11)\quad &92 - 63 = 29 \\ (12)\quad &92 - 69 = 23 \\ (13)\quad &92 - 88 = 4 \\ (14)\quad &96 - 58 = 38 \\ (15)\quad &96 - 59 = 37 \\ (16)\quad &96 - 77 = 19 \\ (17)\quad &96 - 74 = 22 \\ (18)\quad &96 - 91 = 5 \end{aligned}$$

\]

Calculate B150a column subtractions

\[

$$\begin{aligned} (1)\quad &63 - 20 = 43 \\ (2)\quad &63 - 25 = 38 \\ (3)\quad &63 - 48 = 15 \\ (4)\quad &63 - 36 = 27 \\ (5)\quad &72 - 33 = 39 \\ (6)\quad &72 - 51 = 21 \\ (7)\quad &72 - 57 = 15 \\ (8)\quad &72 - 64 = 8 \end{aligned}$$

\]
</reasoning>

<answer>

Page B149b

No.	Problem	Answer
(10)	\(92 - 44\)	\(48\)
(11)	\(92 - 63\)	\(29\)
(12)	\(92 - 69\)	\(23\)
(13)	\(92 - 88\)	\(4\)
(14)	\(96 - 58\)	\(38\)
(15)	\(96 - 59\)	\(37\)
(16)	\(96 - 77\)	\(19\)
(17)	\(96 - 74\)	\(22\)
(18)	\(96 - 91\)	\(5\)

Page B150a

No.	Problem	Answer
(2)	\(63 - 25\)	\(38\)
(3)	\(63 - 48\)	\(15\)
(4)	\(63 - 36\)	\(27\)
(5)	\(72 - 33\)	\(39\)
(6)	\(72 - 51\)	\(21\)
(7)	\(72 - 57\)	\(15\)
(8)	\(72 - 64\)	\(8\)

</answer>

<post_analysis>
{
"subject": "Mathematics",
"question_type": "Free Response",
"knowledge_point": [
"Mathematics",
"Algebra",
"Column Subtraction"
]
}
</post_analysis>

Answer:

<pre_analysis>
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"question_count": 18,
"skills_matched": [
"step_cot",
"table_formatter",
"explain_then_answer",
"quick"
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"concepts_used": [],
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"Column Subtraction",
"Subtraction with Regrouping"
],
"current_concepts": [
"Column Subtraction",
"Subtraction with Regrouping"
]
}
</pre_analysis>

<reasoning>

Calculate B149b column subtractions

\[

$$\begin{aligned} (9)\quad &92 - 47 = 45 \\ (10)\quad &92 - 44 = 48 \\ (11)\quad &92 - 63 = 29 \\ (12)\quad &92 - 69 = 23 \\ (13)\quad &92 - 88 = 4 \\ (14)\quad &96 - 58 = 38 \\ (15)\quad &96 - 59 = 37 \\ (16)\quad &96 - 77 = 19 \\ (17)\quad &96 - 74 = 22 \\ (18)\quad &96 - 91 = 5 \end{aligned}$$

\]

Calculate B150a column subtractions

\[

$$\begin{aligned} (1)\quad &63 - 20 = 43 \\ (2)\quad &63 - 25 = 38 \\ (3)\quad &63 - 48 = 15 \\ (4)\quad &63 - 36 = 27 \\ (5)\quad &72 - 33 = 39 \\ (6)\quad &72 - 51 = 21 \\ (7)\quad &72 - 57 = 15 \\ (8)\quad &72 - 64 = 8 \end{aligned}$$

\]
</reasoning>

<answer>

Page B149b

No.	Problem	Answer
(10)	\(92 - 44\)	\(48\)
(11)	\(92 - 63\)	\(29\)
(12)	\(92 - 69\)	\(23\)
(13)	\(92 - 88\)	\(4\)
(14)	\(96 - 58\)	\(38\)
(15)	\(96 - 59\)	\(37\)
(16)	\(96 - 77\)	\(19\)
(17)	\(96 - 74\)	\(22\)
(18)	\(96 - 91\)	\(5\)

Page B150a

No.	Problem	Answer
(2)	\(63 - 25\)	\(38\)
(3)	\(63 - 48\)	\(15\)
(4)	\(63 - 36\)	\(27\)
(5)	\(72 - 33\)	\(39\)
(6)	\(72 - 51\)	\(21\)
(7)	\(72 - 57\)	\(15\)
(8)	\(72 - 64\)	\(8\)

</answer>

<post_analysis>
{
"subject": "Mathematics",
"question_type": "Free Response",
"knowledge_point": [
"Mathematics",
"Algebra",
"Column Subtraction"
]
}
</post_analysis>