Grade 1 Mathematics Weeks 19–20: Teacher Guide and Answer Key
Suggested daily lesson: 5 minutes review, 10 minutes teacher modeling, 10 minutes guided practice, 10 minutes independent work, and 5 minutes feedback. Adjust to learner needs.
Week 19: Length and comparison
Day 91: Measure in cubes
Teacher model: One strip measures 12 equal-size cubes and another 7. How many cubes longer is the first? Answer: 5. Subtract the lengths in matching units.
Guided answer: 5.
Practice 1: One strip measures 14 equal-size cubes and another 7. How many cubes longer is the first? Answer: 7.
Practice 2: One strip measures 12 equal-size cubes and another 8. How many cubes longer is the first? Answer: 4.
Practice 3: One strip measures 13 equal-size cubes and another 7. How many cubes longer is the first? Answer: 6.
Practice 4: One strip measures 14 equal-size cubes and another 8. How many cubes longer is the first? Answer: 6.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Day 92: Compare ribbons
Teacher model: One strip measures 15 equal-size cubes and another 9. How many cubes longer is the first? Answer: 6. Subtract the lengths in matching units.
Guided answer: 6.
Practice 1: One strip measures 17 equal-size cubes and another 9. How many cubes longer is the first? Answer: 8.
Practice 2: One strip measures 15 equal-size cubes and another 10. How many cubes longer is the first? Answer: 5.
Practice 3: One strip measures 16 equal-size cubes and another 9. How many cubes longer is the first? Answer: 7.
Practice 4: One strip measures 17 equal-size cubes and another 10. How many cubes longer is the first? Answer: 7.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Day 93: Order lengths
Teacher model: Compare 8 and 13: which is greater? Answer: 13. Compare tens, then ones.
Guided answer: 14.
Practice 1: Compare 10 and 13: which is greater? Answer: 13.
Practice 2: Compare 8 and 14: which is greater? Answer: 14.
Practice 3: Compare 9 and 13: which is greater? Answer: 13.
Practice 4: Compare 10 and 14: which is greater? Answer: 14.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Day 94: Same-size units
Teacher model: One strip measures 10 equal-size cubes and another 6. How many cubes longer is the first? Answer: 4. Subtract the lengths in matching units.
Guided answer: 4.
Practice 1: One strip measures 12 equal-size cubes and another 6. How many cubes longer is the first? Answer: 6.
Practice 2: One strip measures 10 equal-size cubes and another 7. How many cubes longer is the first? Answer: 3.
Practice 3: One strip measures 11 equal-size cubes and another 6. How many cubes longer is the first? Answer: 5.
Practice 4: One strip measures 12 equal-size cubes and another 7. How many cubes longer is the first? Answer: 5.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Day 95: Measurement checkpoint
Teacher model: One strip measures 17 equal-size cubes and another 8. How many cubes longer is the first? Answer: 9. Subtract the lengths in matching units.
Guided answer: 9.
Practice 1: One strip measures 19 equal-size cubes and another 8. How many cubes longer is the first? Answer: 11.
Practice 2: One strip measures 17 equal-size cubes and another 9. How many cubes longer is the first? Answer: 8.
Practice 3: One strip measures 18 equal-size cubes and another 8. How many cubes longer is the first? Answer: 10.
Practice 4: One strip measures 19 equal-size cubes and another 9. How many cubes longer is the first? Answer: 10.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Week 20: Time and data
Day 96: Hour
Teacher model: Write 4:00 in words. Answer: 4 o’clock. Minute hand points to 12.
Guided answer: 5 o’clock.
Practice 1: Write 6:00 in words. Answer: 6 o’clock.
Practice 2: Write 4:00 in words. Answer: 4 o’clock.
Practice 3: Write 5:00 in words. Answer: 5 o’clock.
Practice 4: Write 6:00 in words. Answer: 6 o’clock.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Day 97: Half hour
Teacher model: Write 7:30 in words. Answer: half past 7. Minute hand points to 6.
Guided answer: half past 8.
Practice 1: Write 9:30 in words. Answer: half past 9.
Practice 2: Write 7:30 in words. Answer: half past 7.
Practice 3: Write 8:30 in words. Answer: half past 8.
Practice 4: Write 9:30 in words. Answer: half past 9.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Day 98: Count tally marks
Teacher model: 8 + 5 = ___ Answer: 13. Use counters or make a ten.
Guided answer: 15.
Practice 1: 10 + 5 = ___ Answer: 15.
Practice 2: 8 + 6 = ___ Answer: 14.
Practice 3: 9 + 5 = ___ Answer: 14.
Practice 4: 10 + 6 = ___ Answer: 16.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Day 99: Read category data
Teacher model: One strip measures 9 equal-size cubes and another 6. How many cubes longer is the first? Answer: 3. Subtract the lengths in matching units.
Guided answer: 3.
Practice 1: One strip measures 11 equal-size cubes and another 6. How many cubes longer is the first? Answer: 5.
Practice 2: One strip measures 9 equal-size cubes and another 7. How many cubes longer is the first? Answer: 2.
Practice 3: One strip measures 10 equal-size cubes and another 6. How many cubes longer is the first? Answer: 4.
Practice 4: One strip measures 11 equal-size cubes and another 7. How many cubes longer is the first? Answer: 4.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Day 100: Data checkpoint
Teacher model: One strip measures 12 equal-size cubes and another 7. How many cubes longer is the first? Answer: 5. Subtract the lengths in matching units.
Guided answer: 5.
Practice 1: One strip measures 14 equal-size cubes and another 7. How many cubes longer is the first? Answer: 7.
Practice 2: One strip measures 12 equal-size cubes and another 8. How many cubes longer is the first? Answer: 4.
Practice 3: One strip measures 13 equal-size cubes and another 7. How many cubes longer is the first? Answer: 6.
Practice 4: One strip measures 14 equal-size cubes and another 8. How many cubes longer is the first? Answer: 6.
Ask the learner to explain their strategy and check the result with a second representation when possible.
Assessment and privacy
At the end of each week, provide unfamiliar problems of the same types, record independent accuracy and reasoning separately, and reteach misconceptions. Do not publish student scores or claim comprehensive standards alignment from these materials alone.