Mental Math

60 x 30 =

(a)  

(a)   x 50 = 4 500

91 x 7 =

(a)  

15 x 24 =

(a)  

What number when multiplied by itself gives 144 as the answer?

(a)  

What number is 1 less the product of 16 and 4 ?

(a)  

Trevor has eight yellow balloons. His friend, Mike, has three times as many balloons as Trevor. How many balloons does Mike have?

(a)  

Lisa and four of her friends went to lunch. If each person ordered the $22 special, how much did it cost the group for lunch?

(a)  

A restaurant sold 16 sandwiches each day for 30 days. How many sandwiches were sold altogether?

(a)  

11.Each elephant at a zoo eats 100 pounds of hay and 5 pounds of fruits and vegetables everyday. How many pounds of food does the zoo need to feed one elephant for one week?

Use mental math to solve.

• 105 x 7 = (100 x 5) + (100 x 7) = 500 + 700= 1,200

• 105 x 7 = (100x7) + (5x7)= 735 pounds