#!/usr/bin/env python3
"""
Week 27: Equal Groups & Arrays
Phase 5: Multiplication Introduction
Standards: 2.OA.A.4 — use addition to find total objects in rectangular arrays
New Standard:
- Reduced drill (4-6 problems per section)
- Estimation before calculating
- Multiple strategies (groups vs arrays)
- Better word problems (reasoning, real-world equal-group contexts)
- Open-ended challenges (Create Your Own)
- Number talks (explain WITHOUT calculating)
- Friday self-check with emoji 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_multi, tg_sec, tg_note, tg_section_title,
array_svg, eq_group_svg, grid_svg,
star_svg, medal_svg, trophy_svg, check_svg,
times_table_html, skip_count_html, mini_chart_html,
)
from activity_builders import (
build_equal_groups,
build_skip_counting,
build_times_table,
build_challenge_box,
build_two_step_problems,
)
BASE = os.path.expanduser("~/Home_School/2nd_Grade/Math")
WEEK = os.path.join(BASE, "Week_27")
# ═══════════════════════════════════════════════════
# MONDAY — What Are Equal Groups?
# ═══════════════════════════════════════════════════
def monday():
# 1: Fluency warmup — skip count by 2s (connects to equal groups)
s1 = ''\
'
2-min Fluency Warm-up — Skip count by 2s. Fill in the missing numbers.
'
s1 += build_skip_counting({
"sequences": [
{"start": 2, "step": 2, "count": 8, "blank_indices": [3, 6]},
{"start": 2, "step": 2, "count": 8, "blank_indices": [2, 5, 7]},
],
"note": "Skip counting helps us count equal groups fast!"
})
s1 += '
A group is equal when every group has the SAME number of things. '\
'Say it out loud: "3 groups of 4."
'
s2 += build_equal_groups({
"groups": [
{"num_groups": 3, "items_per_group": 4, "blank_total": True},
{"num_groups": 2, "items_per_group": 5, "blank_total": True},
{"num_groups": 4, "items_per_group": 3, "blank_total": True},
{"num_groups": 5, "items_per_group": 2, "blank_total": True},
],
"note": "Count the equal groups. Write how many in ALL."
})
# 3: Write the "groups of" sentence (reduced from 6 to 4)
s3 = 'Look at each picture. Fill in the "groups of" sentence.
'\
''
for g, n in [(2, 4), (3, 3), (4, 2), (2, 6)]:
pic = ''.join(eq_group_svg(n) for _ in range(g))
s3 += f'
{pic}'\
f'
{b("3em")} groups of {b("3em")}
'\
f'
Total: {b("3em")}
'
s3 += '
'\
'
Number Talk — Explain WITHOUT counting every dot.
'\
'
'
s4 += '
Which has MORE cookies?
'\
'
A: 3 bags with 5 cookies each
B: 3 bags with 4 cookies each
'\
'
My thinking: ' + bw() + '
'
s4 += '
Are these the SAME or DIFFERENT totals?
'\
'
A: 2 groups of 6
B: 6 groups of 2
'\
'
My thinking: ' + bw() + '
'
s4 += '
'\
'
Create Your Own — Draw a picture of 4 groups of 3. '\
'You can draw stars, apples, dots — anything you like!
'\
'
'\
'
How many in all? ' + b("4em") + '
'\
'
How did you count them? ' + bw() + '
'\
'
'\
'
2-min Fluency Warm-up — Skip count by 5s.
'
s1 += build_skip_counting({
"sequences": [
{"start": 5, "step": 5, "count": 8, "blank_indices": [2, 5]},
{"start": 5, "step": 5, "count": 8, "blank_indices": [3, 6, 7]},
],
"note": "Count by 5s — fast like counting nickels!"
})
s1 += '
An array puts things in neat rows (across ➡) and '\
'columns (down ⬇). We say "3 rows of 4."
'\
''
for r, c in [(3, 4), (2, 5), (4, 3), (2, 6)]:
s2 += f'
{array_svg(r, c)}'\
f'
{b("3em")} rows of {b("3em")}
'\
f'
Total dots: {b("3em")}
'
s2 += '
'\
'
Estimate First! Take a quick peek — do NOT count yet. '\
'Write your estimate, THEN count by rows to check.
'\
'
'
for r, c in [(4, 5), (3, 6)]:
s3 += f'
{array_svg(r, c)}'\
f'
My estimate: {b("3em")}
'\
f'
Actual count: {b("3em")}
'\
f'
Was your estimate close?
'
s3 += '
Add each ROW to find the total. Example: 3 rows of 4 → 4 + 4 + 4 = 12.
'\
''
for r, c in [(3, 5), (2, 4), (4, 2), (3, 3)]:
s4 += f'
{array_svg(r, c)}'\
f'
Addition equation: ' + bw("12em") + '
'\
f'
Total: {b("3em")}
'
s4 += '
'\
'
Show Two Different Ways — Find the total for this array two ways: '\
'(1) add the rows, (2) add the columns.
'\
f'{array_svg(3, 4)}'\
'
Way 1 (rows): 4 + 4 + 4 = ' + b("3em") + '
'\
'
Way 2 (columns): 3 + 3 + 3 + 3 = ' + b("3em") + '
'\
'
What do you notice about the two answers? ' + bw() + '
'\
'
'\
'
2-min Fluency Warm-up — Skip count by 10s.
'
s1 += build_skip_counting({
"sequences": [
{"start": 10, "step": 10, "count": 8, "blank_indices": [3, 5]},
{"start": 10, "step": 10, "count": 8, "blank_indices": [2, 6, 7]},
],
"note": "Count by 10s — like counting dimes!"
})
s1 += '
Some pictures show groups, some show arrays. Find each total.
'\
''
s2 += f'
{eq_group_svg(4)}{eq_group_svg(4)}{eq_group_svg(4)}'\
f'
3 groups of 4 = {b("3em")}
'
s2 += f'
{array_svg(2, 6)}'\
f'
2 rows of 6 = {b("3em")}
'
s2 += f'
{eq_group_svg(5)}{eq_group_svg(5)}'\
f'
2 groups of 5 = {b("3em")}
'
s2 += f'
{array_svg(4, 4)}'\
f'
4 rows of 4 = {b("3em")}
'
s2 += '
'\
'
Draw the groups or the array. Then find the answer.
'\
'
'
problems = [
("A muffin tin has 3 rows. Each row holds 4 muffins. Mom filled every spot. How many muffins did she bake?", "muffins"),
("Diego puts his toy cars in 4 equal rows. Each row has 5 cars. How many toy cars does Diego have?", "cars"),
]
for text, unit in problems:
s3 += f'
{text}
'\
'
Draw your groups or array: ' + bw() + '
'\
'
' + b("5em") + f' {unit}
'
s3 += '
'\
'
Mia says each picture shows equal groups. Is she right? Circle ✓ or ✗ and explain.
'\
'
'
s4 += f'
{eq_group_svg(4)}{eq_group_svg(4)}{eq_group_svg(3)}'\
'
Equal groups? ✓ or ✗
'\
'
Explain: ' + bw() + '
'
s4 += f'
{eq_group_svg(3)}{eq_group_svg(3)}{eq_group_svg(3)}{eq_group_svg(3)}'\
'
Equal groups? ✓ or ✗
'\
'
Explain: ' + bw() + '
'
s4 += '
'\
'
Create Your Own — Draw an array that has exactly 12 dots. '\
'Hint: there is more than one way!
'\
'
'\
'
My array has ' + b("3em") + ' rows of ' + b("3em") + '
'\
'
Can you think of a DIFFERENT array with 12 dots? '\
'Write it: ' + bw() + '
'\
'
'\
'
2-min Fluency Warm-up — What comes next? Fill in the blank.
'\
'
'
for seq in ["2, 4, 6, ___", "5, 10, 15, ___", "10, 20, 30, ___", "4, 6, 8, ___"]:
s1 += f'
{seq.replace("___", b("3em"))}
'
s1 += '
'\
'
Read carefully. Think: how many groups? How many in each group? Draw if it helps!
'\
'
'
problems = [
("A classroom has 5 tables. Each table seats 4 students. Every seat is taken. How many students are in the classroom?", "students"),
("Grandma plants 3 rows of tomato plants in her garden. Each row has 6 plants. How many tomato plants did she plant?", "plants"),
("An egg carton has 2 rows with 6 eggs in each row. How many eggs fit in the carton?", "eggs"),
]
for text, unit in problems:
s2 += f'
{text}
'\
'
Draw or write your thinking: ' + bw() + '
'\
'
' + b("5em") + f' {unit}
'
s2 += '
'\
'
Solve step by step. Write each answer as you go.
'\
+ build_two_step_problems({
"problems": [
{
"text": "A bakery tray holds 4 rows of 5 cookies. The baker fills one whole tray, then sells 8 cookies. How many cookies are left on the tray?",
"blanks": 2
}
],
"note": "Step 1: find the total on the tray. Step 2: subtract what was sold."
}) + '
'\
'
Number Talk — Explain WITHOUT counting every dot.
'\
'
'
s4 += f'
A: {array_svg(2, 6, width="100")}
B: {array_svg(6, 2, width="40")}
'\
'
Do A and B have the same number of dots?
'\
'
My thinking: ' + bw() + '
'
s4 += '
Rosa has 4 boxes of 3 crayons. Sam has 3 boxes of 3 crayons.
'\
'
Who has more? How do you KNOW without counting?
'\
'
My thinking: ' + bw() + '
'
s4 += '
'\
'
Create Your Own Word Problem
'\
'
Write an equal-groups word problem about something you like '\
'(stickers, dinosaurs, snacks...). Use the words "rows" or "groups." Then solve it.
'\
'
'\
'
'\
'
My picture or thinking: ' + bw() + '
'\
'
Answer: ' + bl() + '
'\
'
'\
'
2-min Fluency Warm-up — Fill in the missing numbers. Go fast!
'
s1 += build_skip_counting({
"sequences": [
{"start": 2, "step": 2, "count": 8, "blank_indices": [4, 7]},
{"start": 5, "step": 5, "count": 8, "blank_indices": [3, 6]},
],
"note": "Count by 2s, then by 5s."
})
s1 += '
'\
'
Estimate First! Peek quickly, estimate, then count by rows to check.
'\
'
'
for r, c in [(5, 4), (3, 7)]:
s2 += f'
{array_svg(r, c)}'\
f'
My estimate: {b("3em")}
'\
f'
Actual: {b("3em")}
'
s2 += '
Fill in the sentence AND the addition equation for each.
'\
''
s3 += f'
{eq_group_svg(5)}{eq_group_svg(5)}{eq_group_svg(5)}'\
f'
{b("3em")} groups of {b("3em")} = {b("5em")}
'\
'
Addition: ' + bw("10em") + '
'
s3 += f'
{array_svg(4, 3)}'\
f'
{b("3em")} rows of {b("3em")} = {b("5em")}
'\
'
Addition: ' + bw("10em") + '
'
s3 += f'
{eq_group_svg(2)}{eq_group_svg(2)}{eq_group_svg(2)}{eq_group_svg(2)}'\
f'
{b("3em")} groups of {b("3em")} = {b("5em")}
'\
'
Addition: ' + bw("10em") + '
'
s3 += f'
{array_svg(3, 6)}'\
f'
{b("3em")} rows of {b("3em")} = {b("5em")}
'\
'
Addition: ' + bw("10em") + '
'
s3 += '
'\
'
Show your thinking with a drawing or equation.
'\
'
'
problems = [
("A parking lot has 4 rows of cars with 5 cars in each row. How many cars are parked?", "cars"),
("Nina fills 3 baskets with 6 apples each. How many apples in all?", "apples"),
]
for text, unit in problems:
s4 += f'
{text}
'\
'
Draw or write your thinking: ' + bw() + '
'\
'
' + b("5em") + f' {unit}
'
s4 += '
'\
'
Self-Check: How do you feel about equal groups and arrays?
'\
'
'\
'
'\
'
Making Equal Groups
'\
'
😊 I got it! | 😐 Getting there | 😟 Need help
'\
'
'\
'
'\
'
Arrays (Rows & Columns)
'\
'
😊 I got it! | 😐 Getting there | 😟 Need help
'\
'
'\
'
'\
'
Addition Equations for Arrays
'\
'
😊 I got it! | 😐 Getting there | 😟 Need help
'\
'
'\
'
'\
'
One thing I learned this week: ' + bl() + '
'\
'
One thing I want to practice more: ' + bl() + '
'\
'
My favorite way to count a group (rows, columns, or skip counting): ' + bl() + '
'\
'