Question

solve.
3 make a ten to subtract. fill in the missing numbers to show 12 - 4 = 8.
4 complete the number sentences.
12 - □ = 10 16 - □ = 10
13 - □ = 10 15 - □ = 10
5 fill in the missing numbers to find 15 - 9.
15 - 9 = 6
15 - 9 = 6
6 jan circled the problems that she cannot solve in her head by making a ten.
14 - 7 8 - 2 12 - 8
9 - 4 15 - 6
look at all of the problems. why doesnt jan make a ten to solve the circled problems?

Explanation:

Step1: Solve 12 - 4 using make - a - ten method

We know that 12 can be split into 10 + 2. First, we subtract 2 from 4 to get to 10. So the first number above the arrow from 12 to 10 is 2. Then from 10 we subtract the remaining 2 to get to 8. So the second number above the arrow from 10 to 8 is 2.

Step2: Complete number sentences

For 12−□ = 10, we find the number by subtracting 10 from 12. 12 - 10=2. For 16−□ = 10, 16 - 10 = 6. For 13−□ = 10, 13 - 10 = 3. For 15−□ = 10, 15 - 10 = 5.

Step3: Solve 15 - 9 using make - a - ten method

15 can be split into 10+5. First, we subtract 5 from 9 to get to 10. So the number above the arrow from 15 to 10 is 5. Then from 10 we subtract the remaining 4 to get to 6. So the number above the arrow from 10 to 6 is 4, and 15 - 9 = 6.

Step4: Analyze non - make - a - ten problems

Jan circled 8 - 2 and 9 - 4. The make - a - ten method is used when we can break down a number to get to 10 easily in subtraction. In 8 - 2 and 9 - 4, the numbers are small enough that we can directly subtract without the need to make a ten.

Answer:

1. First box: 2; Second box: 2
2. 12−2 = 10; 16−6 = 10; 13−3 = 10; 15−5 = 10
3. First box above arrow from 15 to 10: 5; Second box above arrow from 10 to 6: 4; Answer: 6
4. The circled problems (8 - 2 and 9 - 4) are small - number subtractions that can be done directly without the need to make a ten.