Question

The model bellow represents the expression 5x18 . How many tens will there be in in the final product

Answer 1

Consider the expression
`5 * 18`

Expanding 18 as (10+8),

=
`5 * (10+8)`

By using distributive property, we get

=
`( 5 * 10) + ( 5 * 8)`

= 50 + 40

By adding, we get

= 90

The digit at units place is '0' and the digit at tens place is '9'.

Therefore, there are 9 tens in the final product of
`5 * 18`.