Question

activity 1
write the fact family for the group of numbers.
model 20, 90, and 110 20 + 90 = 110 110 − 90 = 20
90 + 20 = 110 110 − 20 = 90

1. 60, 70, and 130 2. 20, 30, and 50 3. 10, 50, and 60
2. 200, 700, and 900 5. 700, 900, and 1,600 6. 900, 900, and 1,800

activity 2
find the difference using expanded subtraction. then write the answer in
standard form.
model
176 100 | 70 | 6 100 | 60 + 10 | 6
− 29 → − | 20 | 9 → − | 20 | 9
100 | 60 | 10 + 6 100 | 60 | 16
→ − | 20 | 9 → − | 20 | 9
100 | 40 | 7 → 100 + 40 + 7 = 147

1. 718 2. 856 3. 426 4. 632

− 522 − 63 − 157 − 195
activity 3 • distributed practice
add.

1. 237 2. 572 3. 653

+ 898 + 489 + 757

1. 999 5. 176 6. 483

+ 312 + 845 + 268

Explanation:

Activity 1

Step1: Write addition facts

For each number set, create 2 addition equations.

Step2: Write subtraction facts

For each number set, create 2 subtraction equations.

Step1: Expand numbers by place value

Break each number into hundreds, tens, ones.

Step2: Regroup if needed

Adjust place values when subtracting smaller from larger digits.

Step3: Subtract each place value

Calculate difference for hundreds, tens, ones.

Step4: Combine to standard form

Sum the resulting place values.

Step1: Add digits from right to left

Start with ones place, then tens, then hundreds.

Step2: Carry over values ≥10

If sum of digits ≥10, carry over to next higher place.

Step3: Combine all place sums

Sum the final values of each place.

Answer:

1. $60 + 70 = 130$; $70 + 60 = 130$; $130 - 70 = 60$; $130 - 60 = 70$
2. $20 + 30 = 50$; $30 + 20 = 50$; $50 - 30 = 20$; $50 - 20 = 30$
3. $10 + 50 = 60$; $50 + 10 = 60$; $60 - 50 = 10$; $60 - 10 = 50$
4. $200 + 700 = 900$; $700 + 200 = 900$; $900 - 700 = 200$; $900 - 200 = 700$
5. $700 + 900 = 1600$; $900 + 700 = 1600$; $1600 - 900 = 700$; $1600 - 700 = 900$
6. $900 + 900 = 1800$; $900 + 900 = 1800$; $1800 - 900 = 900$; $1800 - 900 = 900$

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Activity 2