Working Backwards

Riaz thinks of a number.

He says,

'Halve my number and then add 17

The answer is 23’

What is Riaz's number?

Lara chooses a number less than 100

She divides it by 3 and then subtracts 11

She then divides this result by 2

Her answer is 10.5

What was the number she started with?

Tags

CCSS.7.EE.B.4A

Lara chooses a number less than 20

She divides it by 2 and then adds 6

She then divides this result by 3

Her answer is 4.5

What was the number she started with?

Tags

CCSS.7.EE.B.4A

Daniel has lots of pets. He has four more goldfish than he has turtles. He has one less canary than goldfish. Six of his pets are birds (canaries and parrots). He has two parrots. How many pets does Daniel have?

Jemima has twice as much money as Matthew. Jemima has four times as much money as Sally. Sally has $3 more than Andrew. If Matthew has $14, how much money does Andrew have?

Tags

CCSS.8.EE.C.7B

Jack, Terence, Sharon and Alex are neighbours. Jack is half as old as Sharon. Sharon is three years older than Alex. Alex’s and Sharon’s ages added together equal 17 years. Terence is eight. Who is the youngest?

Tags

CCSS.8.EE.C.7B