Mental Math
What number makes the sentence true?
28 + 79 = _____ + 28
79
Estimate: 3,823 + 3,219
(Round to the thousands place.)
7,000
Victor ate 839 hamburgers. Freddy ate the same amount of hamburgers. How many hamburgers did they eat altogether?
1,678 hamburgers
Mr. Jamison read at the library for 7,939 minutes. Ms. Jamison read at the library for 3,213 minutes. How many more minutes did Mr. Jamison read?
4,726 minutes
Ms. Crough milks her cows twice a day. This morning she got 365 gallons of milk. This evening she got 380 gallons. Then, she sold 612 gallons to the local ice cream factory. How many gallons of milk does she have left?
133 gallons
What number makes the sentence true?
2 + (3 + 1) = (2 + ____) + 1
3
Estimate: 519,348 + 283,193
(Round to the thousands place.)
802,000
2,193 + 7,189
9,382
812,383 - 300,372
512,011
Ms. Bruce has 982 pounds of grain. She feeds 240 pounds to her pigs and 460 to her cows. How many pounds of grain does she have left?
282 pounds of grain
What number makes the sentence true?
75 + 20 = 50 + ______ + 20
25
Estimate: 917,189 - 642,137
(Round to the nearest hundred.)
275,100
523,948 + 284,182
808,130
993,034 - 389,341
603,693
Ms. Williamson baked 200 loaves of bread on Monday morning. She sold 93 loaves in the morning and 39 loaves in the afternoon. How many loaves of bread did she have left?
107 loaves left
Garrett drove 239 miles on Saturday and 149 miles on Sunday. To find 239 + 149 using mental math, Garrett made one of the numbers a multiple of ten as shown below. What is the missing number?
239 + 149 = 240 + _____ = 388
148
Estimate: 594,389 - 435,727
(Round to the nearest hundred.)
158,700
895,193 + 234,510
1,129,703
70,009 - 23,478
46,531
Ms. McInnis brought 80 cupcakes to school on her birthday. She gave a cupcake to each of the 23 students in her class. Later, she gave 35 cupcakes to her teacher friends. How many cupcakes does Ms. McInnis have left?
22 cupcakes
Jillian was training for a marathon. She needs to run a total of 402 miles according to her training plan. So far, she has run 195 miles. In order to mentally determine how much more she needed to run, she adjusted the numbers in her head as shown below. What number is missing?
402 - 195 = 400 - _______ = 207
193
Guerrero collected 73,213 empty soda cans. Red Bird collected 39,422 empty soda cans. ABOUT how many more soda cans did Guerrero collect? Estimate your answer by rounding to the nearest thousand.
112,000
Use a bar model to represent and solve this problem. There were 5,393 people at the state fair on Friday. On Saturday there were 6,119 people at the state fair. How many people were at the fair altogether on both days?
11,512 people
Use a bar model to represent and solve this problem. Oscar wants to save $5,300 to go to Disneyland. If he has already saved 3,278 how much more does he need to save?
$2,022
In fourth grade there were 96 students at the start of the year. During the year 28 students moved away and 42 new students came to school. How many students were in fourth grade at the end of the year?
110 students