Write the numerical expressions
1a. The sum of 21 and 4, doubled
the sum of 21 and 4 is 21+4
doubled means multiplied by 2
2 x (21 + 4)
2a. 10 x (2.5 + 13.5)
ten times the sum of 2.5 and 13.5
1b. 5 times the sum of 7 and 23
5 times is the same as 5 x
the sum of 7 and 23 is 7 + 23
5 x (7 + 23)
2b. (98 - 78) x 11
Eleven times the difference between 98 and 78
1c. 2 times the difference between 49.5 and 37.5
2 times is 2 x
the difference between 49.5 and 37.5 is 49.5-37.5
2 x (49.5-37.5)
2c. (71 + 29) x 26
Twenty six times the sum of 71 and 29
1d. the sum of 3 fifteens and 4 twos
the sum of means add
3 fifteens is 3 x 15
4 twos is 4 x 2
(3 x 15) + (4 x 2)
3a. 93 x (40 + 2) _____ (40 + 2) x 39
Explain your answer.
93 is bigger than 39
So 93 times (40 + 2) will give me a bigger answer than 39 times (40 + 2)
So the answer is >
1e. the difference between 9 thirty-sevens and 8 thirty-sevens
the difference between means subtraction
9 thirty-sevens is 9 x 37
8 thirty-sevens is 8 x 37
(9 x 37) - (8 x 37)
3b. 61 x 25 _____ 60 twenty-fives minus 1 twenty-five
60 twenty-fives is (60 x 25)
1 twenty-five is (1 x 25)
This is the same as (60 x 25) - (1 x 25)
Simplified, this is the same as 59 x 25
So 61 x 25 < (60 x 25) - (1 x 25)
61 x 25 < 59 x 25