Topic 2: Math Review

Question #1 Becky has a secret number. To the nearest ten, her number rounds to 190. Which could be Becky’s number? A. 109 B. 910 C. 201 D. 193

Question #2 Hector is collecting16 markers in a shoe box. He has 9 markers so far. Which number sentence shows a way to find out how many more markers Hector needs to put in the shoe box? A. 16 - n = 10 B. 9 + 16 = n C. 9 + n = 16 D. 9 + 9 = 16

Question #3 Jane is in a jump roping contest. She jumps 354 times for one song. Then she jumps 203 times during the next song .She wants to be able to tell Mr. Brophy the closest estimate, honestly. Which number sentence shows the best estimate of how many total jumps Jane has done so far, using compatible numbers? A. 200 + 350 = 550 B. 400 + 200 = 600 C. 354 + 203 = 557 D. 400 - 200 = 200

Question #4 The lunchroom has 142 seats. Children are sitting in 87 of the seats. Which is the best estimate of the number of empty seats? A. 140 – 90 = 50 empty seats B. 200 – 100 = 100 empty seats C. 150 + 90 = 240 empty seats D. 140 + 90 = 230 empty seats

Question #5 Which number sentence is shown? A. 6 + 4 = 10 B. 10 – 4 = 6 C. 4 + 10 = 14 D. 10 – 6 = 4

Question #6 Alice got $54 for her birthday. She spent some while she was shopping. When she got home, she had $29 left. Use mental math to find out exactly how much she spent at the stores. A $54 + $29 = $813 B. $54 - $29 = #55 - $30 = $25 C. $54 - $ 54 = $0 D. $$50 - $30 = $20

Question #7 The award committee was going to give out banners to all the winners. Which number sentence can be used to find how many banners they made in all? A. 7 – 3 = 4 B. 3 + 7 = 10 C. 7 – 4 = 3 D. 3 + 4 = 7

Question #8 The PTO collected $ 789 from the Texas Road House fund raiser. What is $789 rounded to the nearest hundred? A $790 B. $780 C $800 D. $700

Question #9 Emily read 47 minutes on Friday night and 34 on Saturday night. She used mental math to add her total minutes on the weekend. Which way did Emily get her total correctly? A. 100 + 100 = 200 minutes B. 50 + 40 = 90 minutes C. 47 + 34 = 70 minutes D. 47 + 34 = (40 + 30) + (7 + 4) 70 + 11 = 81 minutes

Question #10 Find the value for n that will make the following equation true. A. 17 = 4 + n 17- 4 = n n = 13 B. 17+ 4 = n 4 + 17 = n n = 13 C. 17 – n = 17 n + 17 = 17 n = 13 D. 4 + 3 = n n – 3 = 4 n = 13

Question #11 Emily read 47 minutes on Friday night and 34 on Saturday night. Is 100 a reasonable answer for the total number of minutes Emily read on the weekend? Explain. A. Yes, because Emily likes to read. B. No, because 47 – 34 does not equal 100. C. No, because Emily could have read more on Sunday. D. Yes, because 47 rounds to 50 and 34 rounds to 30. 50 + 30 = 80. 80 is close to 100 .

Question #12 Find the value of n that will make the following equation true. A. 21 – n = 8 21 – 8 = n n = 8 B. 25 – n = 11 25 + 11 = n n = 36 C. 21 - n =17 21 – 17 = n n = 4 D. 25 – n = 15 25 – 15 = n n = 1

Question #13 One way Mr. Miller subtracted 184 – 18 mentally, was to turn 18 into 20 by adding 2 184 –20 = 164. What does he have to do to 164 to fix the difference? A. add 2 more B. add 100 more C. subtract 2 D. subtract 2 and then subtract 2 and then subtract 2

Question #14 Mrs. Miller’s class brought in 55 pairs of socks. Mr. Gardner’s class brought in 195 pairs. Give a best estimate for the total number of socks the two classes brought to school. (Show the round.) A. 55 + 195 255 B. 55 + 195 260 45 + 200 = 255 60 + 200 = 260 C. 55 + 195 240 D.. 55 + 195 200 50 + 190 = 240 100 + 100 = 200

Question #15 McDonald’s got 783 kid prizes. They gave 264 prizes away on Saturday. Estimate how many prizes McDonald’s had left to give away on Sunday. Round to the nearest ten to estimate your answer. A. 783 + 264 1,040 B. 783 + 783 1.560 780 + 260 = 1,040 780 + 780 = 1,560 783 – 264 500 D. 783 – 264 520 800 – 300 = 500 780 – 260 = 520

Question #16 The pet store has 52 goldfish and 15 betas. Estimate to find how many more goldfish than betas are in the store. A. 52 + 15 70 B. 52 – 15 30 50 + 20 = 70 50 – 20 = 30 C. 52 – 15 40 D. 52 + 15 120 50 – 10 = 40 100 + 20 = 120

Question #17 Sam’s family watched 86 minutes of TV on Friday night and 78 minutes of TV on Saturday night. Use mental math to find out how much more times they watched on Friday than on Saturday. A. 86 + 78 = (80 + 70) + (6 + 8) = 150 + 14 = 164 minutes B. 86 – 78 = (86+2) - (78+2)= 88 – 80 = 8 minutes C. 88 + 78 = 8 + 8 + 7 + 8 = 31 minutes D. 76 – 88 = 10 minutes

Question #18 Round to the nearest hundred to estimate the difference of 719 – 275 = A. 700 – 300 = 400 B. 700 + 300 = 1,000 C. 700 – 200 = 500 D. 700 + 200 = 900 A.

Question #19 What property of addition is shown in the number sentence? Explain. 15 + n = n +15 A. The Identity Property of Addition, because zero plus another number is the other number. B. The Associative of Addition, because the parenthesis can change the groups and get a different sum. C. . The Associative of Addition, because the parenthesis can change the groups and get the same sum. D. The Commutative Property of Addition, because you can change the order of the addends but the sum stays the same.

Question #20 Mrs. SWS had 49 pink marbles and 37 blue marbles. Use the breaking apart strategy in mental math to find out how many total marbles she has. A. 49 + 37 =(40 + 30) + (9 + 7) = 70 + 16 = 86 B. . 49 + 37 =(40 + 70) + (4 + 7) = 110 + 11 = 121 C. 49 - 37 =(40 - 30) - (9 - 7) = 10 - 2 = 8 D. 49 - 37 =(40 + 30) - (9 + 7) = 70 - 16 = 54