Mental Math
Use mental math to solve.
43-10= ___
33
Use an open number line to solve. Show your work.
50-10= ___
40
Use the hundred chart to subtract tens.
70-50=___
a. 70 b. 60 c. 50 d. 20
d. 20
Use the place value blocks to find the difference.
40-20=____ l l l l
20
Jacob has 60 Pokemon cards. He gives 20 to his friend Brooks. How many cards does Jacob have left?
40 cards
Use mental math to solve.
74-20=___
54
Use an open number line to solve. Show your work.
80-20= ___
60
Use the hundred chart to subtract tens.
60-30= ____
a. 60 b. 40 c. 30 d. 20
c. 30
Use the place value blocks to find the difference.
50-30=____ l l l l l
20
Creed has 50 kittens running around his house. He sold 20 to Candice. How many kittens does Creed still have?
Write an equation to solve. Use drawings or models to show your work.
50-20=30
Use mental math to solve. Then, write an addition equation to check your answer.
91-10= ___
81
81+10=91
Use an open number line to solve. Show your work. Explain how you used the number line to find the answer.
90-40= ___
50
Use the hundred chart to subtract tens.
40-30= ____
10
Use the place value blocks to find the difference.
70-30=___ l l l l l l l
40
Caylee has 70 flowers blooming in her garden. She picked 50 and gave them to Addison. How many flowers are left in the garden?
Write an equation to solve. Use drawings or models to show your work.
70-50=20
Use mental math to solve. Then, write an addition equation to check your answer.
55-10= ____
45
45+10=55
Use an open number line to solve. Show your work. Explain how you used the number line to find the answer.
50-40=___
10
Use the hundred chart to subtract tens.
80-50=____
30
Use the place value blocks to find the difference.
87-26= ___ l l l l l l l l ......
61
Ariya has 70 tomatoes to make spaghetti sauce. She smashed 20 of them so far. How many tomatoes have not been smashed yet?
Use addition to solve each subtraction problem.
20+___=70, so
70-20= ____
20+50=70, so
70-20=50
Use mental math to solve. Then, write an addition equation to check your answer.
67-37= ___
30
30+37=67
Use an open number line to solve. Show your work. Explain how you used the number line to find the answer.
56-30=___
26
Use the hundred chart to subtract tens and ones.
78- 60= ___
18
Mrs. Nicklin solved the problem: 34-23 and got 12. Is her answer correct or incorrect. Explain.
Incorrect. 34-23=11. She did not subtract the ones column correctly.
Amelia has 90 tadpoles in her pond. 20 of them turned into frogs. How many tadpoles are left?
Use addition to solve each subtraction problem.
20+___=90, so
90-20= ____
20+70=90, so
90-20=70