multiply(exp10(number), if(modulo(number, 2), 1, -1))

                                                    -1 
                                                    10 
                                                  -100 
                                                  1000 
                                                -10000 
                                                100000 
                                              -1000000 
                                              10000000 
                                            -100000000 
                                            1000000000 
                                          -10000000000 
                                          100000000000 
                                        -1000000000000 
                                        10000000000000 
                                      -100000000000000 
                                      1000000000000000 
                                    -10000000000000000 
                                    100000000000000000 
                                  -1000000000000000000 
                                  10000000000000000000 
                                -100000000000000000000 
                                                  1e21 
                                                 -1e22 
                                                  1e23 
                                                 -1e24 
                                                  1e25 
                                                 -1e26 
                                                  1e27 
                                                 -1e28 
                                                  1e29 
 exp10(number)

             1 
            10 
           100 
          1000 
         10000 
        100000 
       1000000 
      10000000 
     100000000 
    1000000000 
 exp10(number)

             1 
            10 
           100 
          1000 
         10000 
        100000 
       1000000 
      10000000 
     100000000 
    1000000000 
 plus(exp10(number), exp10(negate(number)))

                                          2 
                                       10.1 
                                     100.01 
                                   1000.001 
                                 10000.0001 
                               100000.00001 
                             1000000.000001 
                           10000000.0000001 
                         100000000.00000001 
                                 1000000000