Year 3 Unit 2Assessment task — Adding, subtracting and partitioning numbers: Model response

Part A: Additive number facts

Refer to assessment task Adding, subtracting and partitioning numbers (Part A: Additive number facts) — Model response (slideshow).

1. 4 + 2 = 6 6. 4 + 8 = 12 11. 10 – 2 = 8 16. 12 – 3 = 9

2. 5 + 5 = 10 7. 6 + 6 = 12 12. 8 – 5 = 3 17. 13 – 4 = 9

3. 9 + 3 = 12 8. 5 + 9 = 14 13. 10 – 5 = 5 18. 8 – 6 = 2

4. 2 + 7 = 9 9. 6 + 3 = 9 14. 11 – 5 = 6 19. 13 – 5 = 8

5. 5 + 6 = 11 10. 7 + 7 = 14 15. 9 – 9 = 0 20. 7 – 0 = 7

Part B: Place value understanding

1. Dale’s calculator showed the following number:

What would Dale do to change 796 to become …

a) Circle your answer:

Add 100 Add 10 Add 14 Take away 90 Take away 190

b) Explain your choice:

Dale would add 10. There were 79 tens. When Dale adds 1 ten, the value of the tens increases from 79 tens to 80 tens. Because he added zero ones, the ones place remains the same.

If he added 100, the number would be 896. If he added 14, the number would be 810. If he took 90, the number would be 706 and if he took 190, the calculator display would show 606.

2. How many hundreds are there in the number 702? 7 hundreds

3. On the number expander, write how many tens and ones the number 952 has altogether.

1 of 2Mth_Y03_U2_AT_MR_Number_Ans

259

4. How many hundreds are there in the number 952? 9

5. What number is 10 less than 952? 942

6. Write the number that has 34 tens only. 340

Part C: Problem-solving

1. Eggerling’s Organic Eggs sell their eggs in cartons of 10.

Mini Eggerling, the owner, collected 234 eggs.

How many cartons did she use to pack her eggs?

a) Show your working:

Writing the number on a place value chart or number expander model would show that the 234 has 23 tens and 4 ones.

Students may draw a diagram to show the 23/24 cartons of ten.

Students may explain what happens to the four eggs. For example, Mini only used 23 cartons, the four remaining eggs were put aside for the next packing day or she decided to make an omelette with the four eggs or the four eggs were placed in the 24th box ready for the next packing day.

b) Number of cartons Either 23 or 24 cartons

2. There are 213 cartons in the Eggerling’s van.

There are three shops.

Ten cartons are delivered to each shop.

How many cartons are left in the van after the delivery to shop three?

a) Show your working:

Students identify that 3 tens is 30 and that 213 has 21 tens. They count back from 21 tens, e.g. 20 tens 3 ones, 19 tens 3 ones, 18 tens 3 ones or 183.

Students could draw a diagram to demonstrate how they counted backwards.

Students could write a number sentence to demonstrate how 213 is partitioned to take 30.

b) 183 … cartons are left in the van.

2 of 2Mth_Y03_U2_AT_MR_Number_Ans