#!/usr/bin/env python3
"""
Week 7: Adding Within 100 (No Regrouping) — REWRITTEN
Phase 2: Addition & Subtraction to 100
New Standard:
- Reduced drill (40% fewer problems)
- Added estimation activities
- Multiple strategies encouraged
- Better word problems (reasoning over keywords)
- Real challenges (open-ended thinking)
- Number talks (compare without calculating)
- Friday self-check with reflection
"""
import os
import glob
from weasyprint import HTML
from math_helpers import (
CSS, TEACHER_CSS,
page, page_multi, hdr, sec, b, bw, bl,
tg_page, tg_page_multi, tg_sec, tg_note, tg_section_title,
)
from activity_builders import (
build_column_addition,
build_missing_addend,
)
BASE = os.path.expanduser("~/Home_School/2nd_Grade/Math")
WEEK = os.path.join(BASE, "Week_7")
# ═══════════════════════════════════════════════════
# MONDAY — Adding Tens (Mental Math)
# ═══════════════════════════════════════════════════
def monday():
# 1: Add 10 to any number (reduced from 6 to 4)
s1 = 'When you add 10, only the tens digit changes. The ones stay the same.
'
s1 += ''
for n in [23, 45, 67, 12]:
s1 += f'
'
s1 += '
Add the tens. Keep the ones.
'
s2 += ''
for a, t in [(34, 20), (56, 30), (78, 10), (42, 50)]:
s2 += f'
'
s2 += '
Use the number line. Mark jumps of 10 from the first number.
'
s3 += ''
for a, t in [(25, 30), (47, 40)]:
s3 += f'
{a} + {t} = {b("5em")}
'
start_tick = (a // 10) * 10
end_tick = start_tick + 60
s3 += '
'
s3 += '
'
for tick in range(start_tick, end_tick + 10, 10):
left_pct = ((tick - start_tick) / 60) * 100
s3 += f'
'
s3 += f'
{tick}
'
s3 += '
'
s3 += f'
Mark jumps of 10 starting at {a}
'
s3 += '
'
s3 += '
'
s4 += '
Number Talk — Which sum is bigger? Explain WITHOUT calculating.
'
s4 += '
'
s4 += '
34 + 20 or 34 + 30
My thinking: ' + bw() + '
'
s4 += '
56 + 10 or 56 + 40
My thinking: ' + bw() + '
'
s4 += '
'
s5 += '
Challenge — Add all the tens first, then all the ones.
'
s5 += '
'
for a, c, e in [(20, 30, 45), (10, 50, 23)]:
s5 += f'
{a} + {c} + {e} = {b("6em")}
'
s5 += '
Add the ones, then add the tens. Write the total.
'
s1 += ''
problems = [(23, 45), (34, 54), (42, 36), (53, 24)]
for a, c in problems:
s1 += f'
'
s1 += '
'
s2 += '
Estimate First! About how much?
'
s2 += '
'
for a, c in [(34, 56), (61, 28), (42, 37)]:
at, ao = a // 10, a % 10
ct, co = c // 10, c % 10
s2 += f'
{a} + {c}
'
s2 += f'
Round to tens: {at*10} + {ct*10} = {(at+ct)*10}
'
s2 += f'
About: ' + b('4em') + '
'
s2 += f'
Actual: ' + b('4em') + '
'
s2 += '
Show your work: add ones, add tens, combine.
'
s3 += ''
for a, c in [(24, 35), (43, 56)]:
ao, at = a % 10, a // 10
co, ct = c % 10, c // 10
s3 += f'
{a} + {c}
'
s3 += f'
Ones: {ao} + {co} = ' + b("4em") + '
'
s3 += f'
Tens: {at} + {ct} = ' + b("4em") + '0
'
s3 += '
Total: ' + b("5em") + '
'
s3 += '
'
s4 += '
Use ANY strategy you prefer. Try a different one for each problem.
'
s4 += '
'
for a, c in [(35, 42), (64, 23), (51, 38), (72, 16)]:
s4 += f'
{a} + {c} = {b("5em")}
'
s4 += '
Strategy I used: ' + bw() + '
'
s4 += '
'
s5 += '
Read carefully. Think about what is happening in the situation.
'
s5 += '
'
s5 += '
Sarah has 23 red marbles and 34 blue marbles. She wants to put them all in one jar. How many marbles will be in the jar?
Draw or write your thinking: ' + bw() + '
Answer: ' + b("4em") + ' marbles
'
s5 += '
The library had 45 books on the top shelf and 32 books on the bottom shelf. A student wants to know the total books on both shelves. How many?
Draw or write your thinking: ' + bw() + '
Answer: ' + b("4em") + ' books
'
s5 += '
Line up the numbers. Add ones column, then tens column.
'
s1 = build_column_addition({
"problems": [(23, 45), (34, 54), (42, 36), (53, 24)],
"digits": 2,
"note": "Line up the columns. Add ones first, then tens."
})
# 2: More column practice (reduced from 6 to 4)
s2 = build_column_addition({
"problems": [(35, 42), (51, 38), (72, 16), (45, 24)],
"digits": 2,
"note": "Keep your columns straight!"
})
# 3: Three addends (reduced from 3 to 2)
s3 = 'Add the ones column first, then the tens column.
'
s3 += ''
for a, c, e in [(23, 34, 42), (45, 21, 33)]:
s3 += f'
'
s3 += f'
{a}
'
s3 += f'
+ {c}
'
s3 += f'
+ {e}
'
s3 += '
'
s3 += f'
{b("4em")}
'
s3 += '
'
s3 += '
'
s4 += '
One of these is wrong. Find it, explain the error, and fix it.
'
s4 += '
'
# One wrong: 37+42 should be 79, not 69
s4 += '
23
+ 45
68
✓ or ✗?
If wrong, fix: ' + b("4em") + '
'
s4 += '
37
+ 42
69
✓ or ✗?
If wrong, fix: ' + b("4em") + '
'
s4 += '
'
s5 += '
Create Your Own
'
s5 += '
Make a column addition problem where the answer is 87. Write it and solve it.
'
s5 += '
' + b("3em") + '
'
s5 += '
+ ' + b("3em") + '
'
s5 += '
'
s5 += '
87
'
s5 += '
'
s1 += '
Read carefully. Think about what is happening.
'
s1 += '
'
problems = [
("Emma collected 34 shells on Monday and 42 shells on Tuesday. She wants to make a display with all her shells. How many shells does she have?", 34, 42, "shells"),
("The library has 56 fiction books and 32 non-fiction books. A teacher wants to know the total for her class. How many books?", 56, 32, "books"),
("A farmer has 63 chickens and 24 ducks. He wants to count all his birds. How many birds?", 63, 24, "birds"),
]
for text, a, c, unit in problems:
s1 += f'
{text}
'
s1 += '
Draw or write your thinking: ' + bw() + '
'
s1 += '
' + b("6em") + f' {unit}
'
s1 += '
'
s2 += '
Solve both. Which sum is bigger? Explain WITHOUT calculating first.
'
s2 += '
'
s2 += '
A: 34 + 45 = ' + b("5em") + '
'
s2 += '
B: 52 + 23 = ' + b("5em") + '
'
s2 += '
Before calculating, which do you think is bigger? A or B
'
s2 += '
My thinking: ' + bw() + '
'
s2 += '
After calculating, which is actually bigger? A or B
'
s2 += '
'
s3 += '
Solve step by step. Write each answer.
'
s3 += '
'
s3 += '
Sarah has 23 stickers. Tom gives her 34. Then Mom gives her 20 more. How many does she have now?
'
s3 += '
Step 1: ' + b("6em") + '
'
s3 += '
Step 2: ' + b("6em") + '
'
s3 += '
Total: ' + b("6em") + ' stickers
'
s3 += '
'
s4 += '
Create Your Own Word Problem
'
s4 += '
Write an addition word problem about something you like (sports, animals, games, etc.). Then solve it.
'
s4 += '
'
s4 += '
Answer: ' + bl() + '
'
s4 += '
Solve in your head. Go fast!
'
s1 += ''
for a, t in [(20, 30), (40, 50), (70, 20), (30, 40), (50, 40), (60, 30)]:
s1 += f'
'
s1 += '
Use any strategy you prefer.
'
s3 += ''
for a, c in [(47, 52), (74, 25), (32, 43), (63, 26)]:
s3 += f'
'
s3 += '
'
s4 += '
Read carefully. Show your work.
'
s4 += '
'
problems = [
("A class has 24 boys and 25 girls. The teacher wants to know total students. How many?", 24, 25, "students"),
("Jake read 43 pages on Monday and 36 pages on Tuesday. How many pages total?", 43, 36, "pages"),
]
for text, a, c, unit in problems:
s4 += f'
{text}
'
s4 += '
' + b("6em") + f' {unit}
'
s4 += '
'
s5 += '
Self-Check: How do you feel about adding 2-digit numbers?
'
s5 += '
'
s5 += '
'
s5 += '
Mental Math (Adding Tens)
'
s5 += '
😊 I got it! | 😐 Getting there | 😟 Need help
'
s5 += '
'
s5 += '
'
s5 += '
Column Addition
'
s5 += '
😊 I got it! | 😐 Getting there | 😟 Need help
'
s5 += '
'
s5 += '
'
s5 += '
Word Problems
'
s5 += '
😊 I got it! | 😐 Getting there | 😟 Need help
'
s5 += '
'
s5 += '
'
s5 += '
My favorite strategy for adding 2-digit numbers: ' + bl() + '
'
s5 += '
One thing I want to practice more: ' + bl() + '
'
s5 += '