Part 1: Partition and Use Place Value

1. Partition each decimal into whole numbers, tenths, hundredths and thousandths where needed.

a) 3.47 = ______ + ______ + ______

b) 4.305 = ______ + ______ + ______

2. Complete the place-value scaffold for 6.208.

6 ones = ______

2 tenths = ______

0 hundredths = ______

8 thousandths = ______

Expanded form: 6.208 = __________________________________

3. Write each decimal with matching place-value columns. Then circle the larger number.

a) 4.5 = ______  4.50 = ______

b) 2.5  or  2.45

What must be lined up when adding or subtracting decimals? ____________________________

Part 2: Align, Calculate and Estimate

4. Line up the decimal points and calculate. Show your working.

a) 3.47 + 2.86 = __________

b) 5.00 − 2.68 = __________

5. A drink costs $3.47 and a sandwich costs $5.86. What is the total cost?

Estimate:

Calculate: $________________

The total is reasonable because ________________________________________________

6. Mia has $12.50 and spends $7.85. How much money is left?

Estimate:

Calculate: $________________

7. A ribbon is 2.75 m long. Another ribbon is 1.8 m long. What is their total length?

Estimate:

Calculate: __________________ m

8. A bag weighs 6.00 kg. After 2.65 kg is removed, what is the new mass?

Estimate:

Calculate: __________________ kg

Part 3: Choose and Explain a Strategy

9. Solve 3.76 + 0.24 + 1.5. Tick the strategy or strategies you used.

Estimate:

Answer: __________________

I chose this strategy because _________________________________________________

10. Extension: Solve 4.6 + 2.78 in two different ways. Name each strategy and compare them.

Method 1: ____________________ Method 2: ____________________

The clearer or more efficient method was __________________ because ____________________________

11. Extension: Solve 5.000 − 2.685 in two different ways. Use place-value language in your explanation.

Method 1: ____________________ Method 2: ____________________

12. Explain why 3.47 + 2.86 is not likely to equal 5.33. Use an estimate or place-value reasoning.